US12129422B2 - Abrasive articles and methods of forming same - Google Patents

Abstract

A coated abrasive article comprising a substrate and a plurality of abrasive particles having an average solidity of at least 0.87 and less than 0.97, wherein each of the abrasive particles of the plurality of abrasive particles comprises a body and striations extending along an exterior surface of the body in a direction of a length of the body. Further directed to a plurality of extruded shaped abrasive particles comprising an average solidity of at least 0.87.

Description

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application claims priority under 35 U.S.C. § 119(e) to U.S. Provisional Patent Application No. 62/954,293, filed Dec. 27, 2019, by Samuel S. MARLIN et al., entitled “ABRASIVE ARTICLES AND METHODS OF FORMING SAME,” which is assigned to the current assignee hereof and incorporated herein by reference in its entirety for all purposes.

BACKGROUNDField of the Disclosure

The following is directed to abrasive articles, and in particular, shaped abrasive particles for use in fixed abrasive articles.

Description of the Related Art

Abrasive articles incorporating abrasive particles are useful for various material removal operations including grinding, finishing, polishing, and the like. Depending upon the type of abrasive material, such abrasive particles can be useful in shaping or grinding various materials in the manufacturing of goods. Certain types of abrasive particles have been formulated to date that have particular geometries, such as triangular abrasive particles and abrasive articles incorporating such objects. See, for example, U.S. Pat. Nos. 5,201,916; 5,366,523; and 5,984,988.

Previously, three basic technologies that have been employed to produce abrasive particles having a specified shape, which are fusion, sintering, and chemical ceramic. In the fusion process, abrasive particles can be shaped by a chill roll, the face of which may or may not be engraved, a mold into which molten material is poured, or a heat sink material immersed in an aluminum oxide melt. See, for example, U.S. Pat. No. 3,377,660. In sintering processes, abrasive particles can be formed from refractory powders having a particle size of up to 10 micrometers in diameter. Binders can be added to the powders along with a lubricant and a suitable solvent to form a mixture that can be shaped into platelets or rods of various lengths and diameters. See, for example, U.S. Pat. No. 3,079,243. Chemical ceramic technology involves converting a colloidal dispersion or hydrosol (sometimes called a sol) to a gel or any other physical state that restrains the mobility of the components, drying, and firing to obtain a ceramic material. See, for example, U.S. Pat. Nos. 4,744,802 and 4,848,041. Other relevant disclosures on abrasive particles and associated methods of forming and abrasive articles incorporating such particles are available at: http://www.abel-ip.com/publications/.

The industry continues to demand improved abrasive materials and abrasive articles.

SUMMARY

According to one aspect, a plurality of extruded shaped abrasive particles has an average solidity of at least 0.87.

According to another aspect, a coated abrasive article includes a substrate and a plurality of abrasive particles having an average solidity of at least 0.87 and less than 0.97, wherein each of the abrasive particles of the plurality of abrasive particles comprises a body and striations extending along an exterior surface of the body in a direction of a length of the body.

In another aspect, a method for making shaped abrasive particles includes forming a mixture into a green body and sectioning the green body with minimal distortion to create a plurality of precursor shaped abrasive particles having an average solidity of at least 0.87.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure may be better understood, and its numerous features and advantages made apparent to those skilled in the art by referencing the accompanying drawings.

FIG.1A includes an illustration of a system for forming shaped abrasive particles according to an embodiment.

FIG.1B includes an illustration of a portion of a system for forming shaped abrasive particles according to an embodiment.

FIG.1C includes an illustration of a portion of a system for forming shaped abrasive particles according to an embodiment.

FIG.2A includes an image of a plurality of shaped abrasive particles according to an embodiment.

FIG.2B includes an image of a plurality of shaped abrasive particles according to an embodiment.

FIG.2C includes an image of a shaped abrasive particle in a plane defined by a length and width of the body according to an embodiment.

FIG.2D includes an image of a shaped abrasive particle in a plane defined by a length and width of the body according to an embodiment.

FIG.2E includes an image of an end surface of a shaped abrasive particles like that illustrated inFIG.2C.

FIG.2F includes an image of an end surface of a shaped abrasive particles like that illustrated inFIG.2D.

FIG.3 includes a cross-sectional illustration of a portion of a coated abrasive article according to an embodiment.

FIG.4 includes images of various hook-shaped abrasive particles.

FIG.5 includes a top-view illustration of a portion of a coated abrasive article according to an embodiment.

FIG.6A includes a top-down illustration of a portion of a coated abrasive article according to an embodiment.

FIG.6B includes a perspective view illustration of a portion of a coated abrasive article according to an embodiment.

FIG.7 includes a top-down illustration of a portion of a coated abrasive article according to an embodiment.

FIG.8 includes a side-view illustration of abrasive particles on a backing according to an embodiment.

FIGS.9A and9B include black and white images of abrasive particles having best-fit ellipses according to embodiments herein.

FIG.10 includes a black and white image of an outline of a shaped abrasive particle according to an embodiment for calculation of solidity.

FIG.11 includes a black and white image of an outline of a shaped abrasive particle according to an embodiment for calculation of sharpness.

FIGS.12A and12B include plots of force/area for various abrasive particle samples, including shaped abrasive particles of embodiments herein and conventional abrasive particles.

DETAILED DESCRIPTION

The following description in combination with the figures is provided to assist in understanding the teachings disclosed herein. The following discussion will focus on specific implementations and embodiments of the teachings. This focus is provided to assist in describing the teachings and should not be interpreted as a limitation on the scope or applicability of the teachings. However, other teachings can certainly be used in this application.

As used herein, the terms “comprises,” “comprising,” “includes,” “including,” “has,” “having” or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a method, article, or apparatus that comprises a list of features is not necessarily limited only to those features but may include other features not expressly listed or inherent to such method, article, or apparatus. Further, unless expressly stated to the contrary, “or” refers to an inclusive-or and not to an exclusive-or. For example, a condition A or B is satisfied by any one of the following: A is true (or present) and B is false (or not present), A is false (or not present) and B is true (or present), and both A and B are true (or present).

Also, the use of “a” or “an” is employed to describe elements and components described herein. This is done merely for convenience and to give a general sense of the scope of the invention. This description should be read to include one or at least one and the singular also includes the plural, or vice versa, unless it is clear that it is meant otherwise. For example, when a single embodiment is described herein, more than one embodiment may be used in place of a single embodiment. Similarly, where more than one embodiment is described herein, a single embodiment may be substituted for that more than one embodiment.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The materials, methods, and examples are illustrative only and not intended to be limiting. To the extent that certain details regarding specific materials and processing acts are not described, such details may include conventional approaches, which may be found in reference books and other sources within the manufacturing arts. Moreover, unless stated otherwise, reference to any quantified value will be understood to be an average value based on a statistically-relevant sample size.

The following is directed to shaped abrasive particles, methods of forming shaped abrasive particles, and methods of forming coated abrasive articles including shaped abrasive particles. The abrasive articles may be used in a variety of material removal operations for a variety of work pieces.

FIG.1A includes an illustration of a system for forming shaped abrasive particles according to an embodiment. It will be appreciated that while the illustrated system ofFIG.1A provides an explanation for a process for forming shaped abrasive particles and this embodiment should not be interpreted as limiting. Other processes may be used to form the shaped abrasive particles. Some suitable processes may include, but is not limited to, alternative extrusion techniques, printing, molding, casting, punching, embossing, fracturing, or any combination thereof.

Referring again toFIG.1A, asystem100 can include aproduction tool101 disposed and configured to move aroundrollers105,106,107, and108 (105-108). The production tool can include cavities, which may extend through the entire thickness of theproduction tool101 and facilitate the movement of amixture113 through the cavities. Themixture113 can be extruded by anextruder103 through the cavities in the production tool to facilitate shaping of themixture113 to form precursor shaped abrasive particles.

In one non-limiting embodiment, themixture113 may include at least a ceramic material and a liquid. In particular, themixture113 can be a gel formed of a ceramic powder material and a liquid, wherein the gel can be characterized as a shape-stable material having the ability to hold a given shape even in the green state (i.e., unfired or undried gel). In accordance with an embodiment, the gel can be formed of the ceramic powder material as an integrated network of discrete particles.

In certain aspects, control of certain processing conditions may be suitable for forming shaped abrasive particles. For example, themixture113 may be formed with a particular content of solid material to facilitate suitably forming the shaped abrasive particles. In one embodiment, themixture113 can have a high solids content, including for example, a solids content of at least about 25 wt %, such as at least about 35 wt %, at least about 42 wt %, at least about 44 wt %, at least about 46 wt %, at least about 48 wt %, at least about 50 wt %, at least about 55 wt %, at least about 60 wt %, at least 65 wt % or even at least 68 wt % for the total weight of themixture113. Still, in at least one non-limiting embodiment, the solid content of themixture113 can be not greater than about 90 wt %, such as not greater than about 85 wt %, not greater than about 82 wt %, not greater than about 80 wt %, not greater than about 78 wt %, not greater than about 75 wt %, not greater than about 73 wt %, or even not greater than about 70 wt %. It will be appreciated that the content of the solids materials in themixture113 can be within a range between any of the minimum and maximum percentages noted above.

According to one embodiment, the ceramic powder material can include an oxide, a nitride, a carbide, a boride, an oxycarbide, an oxynitride, a superabrasive material or any combination thereof. It will be appreciated, that in certain alternative embodiments, in place of a ceramic powder material, one may choose to use a precursor of a ceramic powder material. A precursor can be a material, which may or may not be in a powder form that is configured to change at least a portion of its composition or physical properties during processing to form a ceramic material. In particular instances, the ceramic material can include alumina. More specifically, the ceramic material may include a boehmite material, which may be a precursor of alpha alumina. The term “boehmite” is generally used to denote alumina hydrates including mineral boehmite, typically being Al2O3·H2O and having a water content on the order of 15%, as well as pseudoboehmite, having a water content higher than 15%, such as 20-38% by weight. It is noted that boehmite (including pseudoboehmite) has a particular and identifiable crystal structure, and accordingly unique X-ray diffraction pattern, and as such, is distinguished from other aluminous materials including other hydrated aluminas such as ATH (aluminum trihydroxide) a common precursor material used herein for the fabrication of boehmite particulate materials.

Furthermore, themixture113 can be formed to have a particular content of liquid material. Some suitable liquids may include inorganic materials, such as water or various organic materials such as alcohol and the like. In accordance with one embodiment, themixture113 can be formed to have a liquid content less than the solids content of themixture113. In more particular instances, themixture113 can have a liquid content of at least about 10 wt %, such as at least about 12 wt % for the total weight of themixture113. In other instances, the amount of liquid within themixture113 can be greater, such as at least about 15 wt %, at least about 18 wt %, at least about 20 wt %, at least about 22 wt %, at least about 25 wt %, at least about 30 wt %, at least about 35 wt %, or even at least about 40 wt %. Still, in at least one non-limiting embodiment, the liquid content of the mixture can be not greater than about 60 wt %, such as not greater than about 50 wt %, not greater than about 45 wt %, not greater than about 40 wt %, not greater than about 35 wt %, or not greater than about 30 wt %. It will be appreciated that the content of the liquid in themixture113 can be within a range between any of the minimum and maximum percentages noted above.

In some instances, themixture113 may have particular rheological characteristics to facilitate forming the shaped abrasive particles. For example, themixture113 may have a particular storage modulus. In one non-limiting embodiment, themixture113 can have a storage modulus of at least about 1×10⁴Pa, such as at least about 4×10⁴Pa, such as at least about 1×10⁵Pa, at least about 1×10⁶Pa, at least about 1×10⁷Pa, at least about 1×10⁸Pa, at least about 1×10⁹Pa or at least about 1×10¹⁰Pa or even at least about 40×10⁴Pa. In at least one non-limiting embodiment, themixture113 may have a storage modulus of not greater than about 1×10²⁰Pa, not greater than about 1×10¹⁵Pa, not greater than about 1×10¹⁰Pa, or even not greater than about 1×10⁸Pa. It will be appreciated that the storage modulus of themixture113 can be within a range between any of the minimum and maximum values noted above.

The storage modulus can be measured via a parallel plate system using ARES or AR-G2 rotational rheometers, with Peltier plate temperature control systems. For testing, themixture113 can be extruded within a gap between two plates that are set to be approximately 8 mm apart from each other. After extruding the gel into the gap, the distance between the two plates defining the gap is reduced to 2 mm until themixture113 completely fills the gap between the plates. After wiping away excess mixture, the gap is decreased by 0.1 mm and the test is initiated. The test is an oscillation strain sweep test conducted with instrument settings of a strain range between 0.01% to 100%, at 6.28 rad/s (1 Hz), using 25-mm parallel plate andrecording 10 points per decade. Within 1 hour after the test completes, lower the gap again by 0.1 mm and repeat the test. The test can be repeated at least 6 times. The first test may differ from the second and third tests. Only the results from the second and third tests for each specimen should be reported.

In another non-limiting embodiment, themixture113 may have a particular viscosity that facilitates formation of the shaped abrasive particles. For example, themixture113 can have a viscosity of at least about 1×10³Pas, at least about 1×10⁴Pas, at least about 1×10⁵Pas, at least about 1×10⁶Pas, at least about 1×10⁷Pas, at least about 1×10⁸Pas, at least about 1×10⁹Pas, at least about 1×10¹⁰Pas, at least about 1×10¹¹Pas, at least about 1×10¹²Pas, at least about 1×10¹³Pas. In at least one non-limiting embodiment, themixture113 may have a viscosity of not greater than about 1×10²⁰Pas, not greater than about 1×10¹⁸Pas, not greater than about 1×10¹⁵Pas, or even not greater than about 1×10¹²Pas. It will be appreciated that the viscosity of themixture113 can be within a range between any of the minimum and maximum values noted above. The viscosity can be measured in the same manner as the storage modulus as described above.

In still another non-limiting embodiment, themixture113 may have a particular yield stress. For example, themixture113 can have a yield stress of at least about 1×10²Pa, at least about 1×10³Pa at least about 1×10⁴Pa, at least about 1×10⁵Pa, at least about 1×10⁶Pa, at least about 1×10⁷Pa, or at least about 1×10⁸Pas. In at least one non-limiting embodiment, themixture113 may have a yield stress of not greater than about 1×10²⁰Pa, not greater than about 1×10¹⁵Pa, not greater than about 1×10¹²Pa, or even not greater than about 1×10¹⁰Pa. It will be appreciated that the yield stress of themixture113 can be within a range between any of the minimum and maximum values noted above. The yield stress can be measured in the same manner as the storage modulus as described above.

The rheological characteristics of themixture113 can be distinct from conventional mixtures and gels, such as those described in certain references. Moreover, themixture113 can be formed to have a particular relationship between one or more rheological characteristics (e.g., viscosity, yield stress, storage modulus, etc.) to facilitate forming. Notably, the gel may be significantly more “stiff”, having a shear thinning characteristic, which may be entirely distinct from mixtures used in other forming methods.

In some optional embodiments, themixture113 can be formed to have a particular content of organic materials, including for example, organic additives that can be distinct from the liquid, to facilitate processing and formation of shaped abrasive particles according to the embodiments herein. Some suitable organic additives may include stabilizers, binders, such as fructose, sucrose, lactose, glucose, UV curable resins, and the like. It will be appreciated that the total content of all materials in the mixture (e.g., ceramic powder material, water, additives, etc.) add up to and do not exceed 100%.

The embodiments herein may utilize amixture113 that can be distinct from certain types of slurries. For example, the content of organic materials within themixture113, particularly, any of the organic additives noted above may be a minor amount as compared to other components within themixture113. In at least one embodiment, themixture113 can be formed to have not greater than about 30 wt % organic material for the total weight of themixture113. In other instances, the amount of organic materials may be less, such as not greater than about 15 wt %, not greater than about 10 wt %, or even not greater than about 5 wt %. Still, in at least one non-limiting embodiment, the amount of organic materials within themixture113 can be at least about 0.5 wt % for the total weight of themixture113. It will be appreciated that the amount of organic materials in themixture113 can be within a range between any of the minimum and maximum values noted above. In at least one alternative aspect, themixture113 may be essentially free of organic material.

In some embodiments, themixture113 can be formed to have a particular content of acid or base, which may facilitate processing. Some suitable acids or bases can include nitric acid, sulfuric acid, citric acid, hydrochloric acid, tartaric acid, phosphoric acid, ammonium nitrate, and/or ammonium citrate. According to one particular embodiment, themixture113 can have a pH of less than about 5, and more particularly, within a range between at least about 2 and not greater than about 4, using a nitric acid additive. Alternatively, the rheology of the acidic gel can be further modified by converting the acidic gel to a basic gel through the use of bases such as ammonium hydroxide, sodium hydroxide, organics amines such as hexamethylenetetramine and the like.

In one embodiment, extrusion of themixture113 from theextruder103 and through the cavities in theproduction tool101 can include applying a force on themixture113 to facilitate extrusion. In accordance with an embodiment, a particular pressure may be utilized during extrusion. For example, the pressure can be at least about 10 kPa, such as at least about 50 kPa, at least about 100 kPa, at least about 200 kPa or at least about 300 kPa or at least 400 kPa or at least 500 kPa at least about 1,000 kPa, at least about 5,000 kPa or at least about 8,000 kPa or at least 10,000 kPa or at least 15,000 kPa, at least about 20,000 kPa, at least about 30,000 kPa. Still, in at least one non-limiting embodiment, the pressure utilized during extrusion can be not greater than about 100,000 kPa, such as not greater than about 80,000 kPa not greater than about 60,000 kPa or not greater than 50,000 kPa or not greater than 40,000 kPa, not greater than about 30,000 kPa not greater than about 20,000 kPa or not greater than 10,000 kPa or not greater than 8,000 kPa or not greater than 5,000 kPa not greater than about 1,000 kPa not greater than about 800 kPa or not greater than 600 kPa. It will be appreciated that the pressure used to extrude themixture113 can be within a range between any of the minimum and maximum values noted above.

In another non-limiting aspect, the pressure used to extrude themixture113 may have a particular relationship to the solids loading, which may facilitate certain features of the shaped abrasive particles of the embodiments herein. For example, in one non-limiting embodiment, the mixture may have a solids loading within a range of at least 40 wt % to not greater than 60 wt % and be extruded at a pressure within a range of at least 10 kPa and not greater 10,000 kPa, such as within a range of at least 100 kPa and not greater than 5,000 kPa or within a range of at least 200 kPa and not greater than 1,000 kPa.

In an alternative embodiment, the pressure used to extrude themixture113 may have a particular relationship to the solids loading, which may facilitate certain features of the shaped abrasive particles of the embodiments herein. For example, in one non-limiting embodiment, the mixture may have a solids loading within a range of at least 61 wt % to not greater than 80 wt % and be extruded at a pressure within a range of at least 15,000 kPa and not greater 100,000 kPa, such as within a range of at least 100 kPa and not greater than 5,000 kPa or within a range of at least 200 kPa and not greater than 1,000 kPa.

In accordance with one embodiment, themixture113 can have a coil value of at least about 1800 N. The coil value can be measured on an instrument called a Shimpo compression tester manufactured by Shimpo Instruments, Itasca Illinois, using a sample of mixture ranging from 30-60 grams in mass, which is manually pressed into a plastic/stainless steel cylinder of 2″ in diameter. At the extrusion end of the cylinder, a plastic insert with a cylindrical hole establishes the compressed extrudate size of 0.25 inches in diameter. A plunger slides into the cylinder and when the test is started, the plunger will extrude the gel once the threshold coil force is reached. When the cylinder assembly is in position, the Shimpo compression tester moves a force probe down towards the plunger at a constant rate of 95-97 mm/min. When the threshold coil force is reached, the gel is extruded out of the insert hole and an output meter generates a peak force, which is the coil value. In another embodiment, the coil value of themixture113 can be at least about 200 N, such as at least about 300 N, at least about 400 N, at least about 500 N, at least about 600 N, at least about 700 N, at least about 800 N, at least about 900 N, at least about 1000 N. In one non-limiting embodiment, the coil value can be not greater than about 5000 N, such as not greater than about 4000 N, not greater than about 3000 N or even not greater than 2000 N. Thus, certain mixtures according to the embodiments herein can be significantly more flow resistant compared to conventional mixtures.

In accordance with an embodiment, theproduction tool101 can include cavities in the form of apertures that extend through the thickness of theproduction tool101. Theproduction tool101 may be in the form of an endless belt for continuous operations. Additionally, the production tool may include a plurality of cavities for improving the production capabilities of the process. The cavities can have any two-dimensional shape and size depending upon the intended cross-sectional shape of the shaped abrasive particles. In one particular embodiment, the cavities can have a quadrilateral two-dimensional shape as viewed in the plane of the length and width of theproduction tool101.

As further illustrated inFIG.1A, themixture113 can be extruded through the cavities in theproduction tool101. More specifically, in an embodiment, as the cavities translate past the die opening of theextruder103, themixture113 can be forced from theextruder103 and through the cavities in theproduction tool101. As theproduction tool101 continues to translate, the cavities pass by the die opening, stopping any further extrusion of themixture113 into the filled cavities. Extrusion may continue into the next group of cavities that are exposed to the die opening. Themixture113 that is forced through the cavities can protrude through the cavities on the side of theproduction tool101 that is opposite the side of theproduction tool101 that is adjacent the die opening of theextruder103.

In one embodiment, the rate of translation of theproduction tool101 may be controlled to facilitate the formation of precursor shaped abrasive particles and shaped abrasive particles having one or more features of the embodiments herein. In one particular embodiment, the rate of translation of theproduction tool101 can be controlled relative to the rate of extrusion.

In one non-limiting embodiment, themixture113 may be extruded at an extrusion rate of at least 0.0015 cm/s, such as at least 0.005 cm/s, at least 0.008 cm/s, at least 0.01 cm/s, at least 0.015 cm/s, at least 0.02 cm/s, at least 0.05 cm/s, at least 0.08 cm/s, at least 0.10 cm/s, at least 0.20 cm/s, at least 0.30 cm/s, at least 0.40 cm/s, at least 0.50 cm/s. Still, in one non-limiting embodiment, themixture113 may be extruded at an extrusion rate of not greater than 5 m/s, such as not greater than 1 m/s, not greater than 0.5 m/s, not greater than 100 cm/s, not greater than 50 cm/s, not greater than 10 cm/s, not greater than 1 cm/s. It will be appreciated that themixture113 may be extruded at an extrusion rate within a range between any of the minimum and maximum values noted above.

In one non-limiting embodiment, the production tool may be translated at a translation rate of at least 0.10 cm/s, such as at least 0.50 cm/s, at least 0.80 cm/s, at least 1.0 cm/s, at least 1.5 cm/s, at least 2 cm/s, at least 3 cm/s, at least 4 cm/s, at least 5 cm/s, at least 6 cm/s, at least 7 cm/s, at least 8 cm/s, at least 9 cm/s. Still, in one non-limiting embodiment, theproduction tool101 may be translated at a rate of not greater than 5 m/s, such as not greater than 1 m/s, not greater than 0.5 m/s, not greater than 100 cm/s, not greater than 50 cm/s, not greater than 25 cm/s, not greater than 15 cm/s. It will be appreciated that the production tool may be translated at a rate within a range between any of the minimum and maximum values noted above.

Theproduction tool101 may include an inorganic material, including for example, but not limited a ceramic, a metal, a metal alloy, or any combination thereof. In an alternative embodiment, theproduction tool101 may include an organic material, such as a polymer, including for example, a fluoropolymer, such as polytetrafluoroethylene (PTFE).

In an alternative embodiment, theproduction tool101 may include a specific composition that may be imparted to themixture113 contained on the surfaces of the cavities. For example, the surfaces of the cavities may be coated with an additive. The additive may be an inorganic material, organic material, or any combination thereof. In certain instances, the additive may be a dopant. In such embodiments, themixture113 may be doped while being extruded through the cavities of theproduction tool101.

After extrusion of themixture113, the extruded mixture can be translated on theproduction tool101 to undergo further optional post-shaping processing atstage109. Some non-limiting examples of the post-shaping processing atstage109 may include drying, cooling, spraying, doping, coating, or any combination thereof.

After conducting any optional post-shaping processing atstage109, the extruded mixture can be translated to arelease zone110 where the extruded mixture portions are released from the cavities of theproduction tool101 to form precursor shaped abrasive particles. The extruded mixture portions can be released from theproduction tool101 using various techniques, including but not limited to, mechanical manipulation, vibration, impingement of a gas or liquid phase material, change in temperature (i.e., heating, cooling, freezing, etc.), and the like. In a preferred embodiment, the extruded mixture portions are engaged with a blade that facilitates separation from theproduction tool101. In one non-limiting embodiment, the speed of the blade, rheology of the mixture, and speed of extrusion are adjusted relative to each other to facilitate formation of precursor shaped abrasive particles with minimal deflection and having one or more of the features of the abrasive particles of the embodiments herein.

In accordance with an embodiment, themixture113 can experience a change in weight of less than about 5% for the total weight of themixture113 for the duration themixture113 is connected to theproduction tool101. In other embodiments, the weight loss of themixture113 can be less, such as less than about 4%, less than about 3%, less than about 2%, less than about 1%, or even less than about 0.5%. Still, in one particular embodiment, themixture113 may have essentially no change in weight for the duration themixture113 is in theproduction tool101.

Furthermore, during processing, themixture113 may experience a limited change in volume (e.g., shrinkage) for the duration themixture113 is connected to theproduction tool101. For example, the change in volume of themixture113 can be less than about 5% for the total volume of themixture113, such as less than about 4%, less than about 3%, less than about 2%, less than about 1%, or even less than about 0.5%. In one particular embodiment, themixture113 may experience essentially no change in volume for the entire duration themixture113 is connected to theproduction tool101.

In one non-limiting embodiment, themixture113 may undergo a controlled heating process, while themixture113 is connected to theproduction tool101. For example, the heating process may include heating the mixture at a temperature greater than room temperature for a limited time. The temperature may be at least about 30° C., such as at least about 35° C., at least about 40° C., such as at least about 50° C., at least about 60° C., or even at least about 100° C. Still, the temperature may be not greater than about 300° C., such as not greater than about 200° C., or even not greater than about at least about 150° C., or even not greater than about 100° C. The duration of heating can be particularly short, such as not greater than about 10 minutes, not greater than about 5 minutes, not greater than about 3 minutes, not greater than about 2 minutes, or even not greater than about 1 minute.

The heating process may utilize a radiant heat source, such as infrared lamps to facilitate controlled heating of themixture113. Moreover, the heating process may be adapted to control the characteristics of the mixture and facilitate particular aspects of the shaped abrasive particles according to embodiments herein.

In certain instances, the precursor shaped abrasive particles can be gathered and undergo further processing. For example, further processing can include doping, calcining, impregnating, drying, sintering, and the like. In one embodiment, the precursor shaped abrasive particles may have a dopant material applied to one or more exterior surfaces. In accordance with an embodiment, applying a dopant material can include the application of a particular material, such as a salt, which can be a precursor salt material that includes a dopant material to be incorporated into the finally-formed shaped abrasive particles. For example, a metal salt can include an element or compound that is the dopant material. It will be appreciated that the salt material may be in liquid form, such as in a dispersion comprising the salt and liquid carrier. The salt may include nitrogen, and more particularly, can include a nitrate. In one embodiment, the salt can include a metal nitrate, and more particularly, consist essentially of a metal nitrate.

In one embodiment, the dopant material can include an element or compound such as an alkali element, alkaline earth element, rare earth element, hafnium, zirconium, niobium, tantalum, molybdenum, vanadium, or a combination thereof. In one particular embodiment, the dopant material includes an element or compound including an element such as lithium, sodium, potassium, magnesium, calcium, strontium, barium, scandium, yttrium, lanthanum, cesium, praseodymium, niobium, hafnium, zirconium, tantalum, molybdenum, vanadium, chromium, cobalt, iron, germanium, manganese, nickel, titanium, zinc, silicon, boron, carbon and a combination thereof.

In one embodiment, the precursor shaped abrasive particle may be dried. Drying may include removal of a particular content of material, including volatiles, such as water. In accordance with an embodiment, the drying process can be conducted at a drying temperature of not greater than about 300° C., such as not greater than about 280° C., or even not greater than about 250° C. Still, in one non-limiting embodiment, the drying process may be conducted at a drying temperature of at least about 10° C., such as at least 20° C. or at least 30° C. or at least 40° C. It will be appreciated that the drying temperature may be within a range between any of the minimum and maximum temperatures noted above.

In accordance with an embodiment, the process of forming the shaped abrasive particles may include calcining, which includes removal of volatiles and a phase change in the material, including for example, a high-temperature phase material (e.g., alpha alumina). In yet another embodiment, the process for forming shaped abrasive particles may include impregnation of calcined precursor shaped abrasive particles with a dopant. In another embodiment, formation of the shaped abrasive particles from the precursor shaped abrasive particles can include sintering. Sintering may be conducted to densify the particles. In a particular instance, the sintering process can facilitate the formation of a high-temperature phase ceramic material. For example, in one embodiment, the precursor shaped abrasive particle may be sintered such that a high-temperature phase of alumina, such as alpha alumina is formed. It will be appreciated that certain additional processes, such as cleaning, may be completed on theproduction tool101, to facilitate regular and repetitive processing.

After forming the shaped abrasive particles, such particles may be disposed onto a substrate to form a fixed abrasive article, such as a coated abrasive article. Further details on the coated abrasive articles and methods for forming such articles are described herein.

In an alternative embodiment, themixture113 can be extruded through a die rather than a translating production tool. In such embodiments, the mixture can be extruded through openings in a die and undergo sectioning upon being extruded to a particular length. For these particular embodiments, the sectioning of the mixture to form precursor shaped abrasive particles occurs at or near the surface of the die.

FIGS.1B, and1C include systems that may not necessarily incorporate a translating production tool. Rather, such systems may conduct continuous forming of the precursor shaped abrasive particles by continuous extrusion and simultaneous sectioning. It should be noted that such systems may be modified to utilize a translating production tool and the embodiments herein are not so limited. The systems for forming shaped abrasive particles ofFIGS.1B, and1C, may be suitable for creating shaped abrasive particles having one or more combination of features described herein.

According to one aspect, the process for forming the shaped abrasive particles can include forming themixture113 into a green body and sectioning the green body with minimal distortion to create a plurality of precursor shaped abrasive particles with certain features. Referring toFIG.1B, themixture113 may be formed via extrusion through one ormore openings131 in adie132, which may be positioned at the end of anextruder103. Themixture113 can be extruded through the one ormore openings131 in thedirection134.

In one particular embodiment, as illustrated inFIG.1B, the one ormore openings131 can have aparticular opening axis135 that is angled relative to theprimary extrusion axis140 and/or amajor surface138 of thedie132. The smallest angle between theprimary extrusion axis140 andopening axis135 can be defined as anextrusion angle136, which in some non-limiting embodiments, may be non-parallel to theprimary extrusion axis140.

In one non-limiting embodiment, theextrusion angle136 can be at least 5 degrees, such as at least 8 degrees or at least 10 degrees or at least 15 degrees or at least 20 degrees or at least 25 degrees or at least 30 degrees or at least 35 degrees or at least 40 degrees or at least 45 degrees. Still, in another non-limiting embodiment, theextrusion angle136 may be not greater than 85 degrees, such as not greater than 80 degrees or not greater than 70 degrees or not greater than 60 degrees or not greater than 50 degrees or not greater than 40 degrees or not greater than 30 degrees. It will be appreciated that theextrusion angle136 can be within a range including any of the minimum and maximum values noted above.

According to another embodiment, themixture113 can be formed into a green body as it exits the one ormore openings131. The portion of themixture113 extending from the one or moredie openings131 can be a green body having a cross-sectional shape substantially similar to the cross-sectional shape of the one or moredie openings131. In at least one embodiment, the extrudate, and thus the precursor shaped abrasive particles, and the resulting shaped abrasive particles can have a cross-sectional shape from the group of a regular polygon, an irregular polygon, an ellipse, a circle or any combination thereof.

In one particular aspect, the green body can be sectioned by asectioning device133. Thesectioning device133 may be one or more devices, such as blades or other objects suitable for separating the green body from themixture113. Other suitable devices may include sectioning devices using sectioning mediums that are ejected from the sectioning device and may include a gas and/or a liquid. The separation may be at or near themajor surface138 of thedie132. In the illustrated embodiment ofFIG.1B, thesectioning device133 may be coupled to an actuation device (e.g., a motor) configured to move the sectioning device relative to themajor surface138 of thedie132.

According to one aspect, sectioning can be conducted in a plane non-perpendicular to theopening axis135. In another embodiment, sectioning can be conducted in a plane that is non-perpendicular to the longitudinal axis of the green body as it is extruded from the one ormore openings131 of thedie132. For example, as illustrated in the embodiment ofFIG.1B, theleading edge139 of thesectioning device133, which his configured to conduct sectioning of the green body, defines a plane that is non-perpendicular to theopening axis135 and a longitudinal axis of the green body.

In at least one embodiment, asectioning angle137 is defined as the smallest angle between the openingaxis135 and theleading edge139 of thesectioning device133 as viewed in a plane perpendicular to theextrusion direction134. For example, the sectioningangle137 can be at least 5 degrees, such as at least 8 degrees or at least 10 degrees or at least 15 degrees or at least 20 degrees or at least 25 degrees or at least 30 degrees or at least 35 degrees or at least 40 degrees or at least 45 degrees. Still, in another non-limiting embodiment, the sectioningangle137 may be not greater than 85 degrees, such as not greater than 80 degrees or not greater than 70 degrees or not greater than 60 degrees or not greater than 50 degrees or not greater than 40 degrees or not greater than 30 degrees. It will be appreciated that the sectioningangle137 can be within a range including any of the minimum and maximum values noted above.

According to one aspect, sectioning can create at least one end surface of the precursor shaped abrasive particle and finally-formed shaped abrasive particle that is a cut surface. In one non-limiting embodiment, the cut surface can be at an end of a body of a precursor shaped abrasive particle or shaped abrasive particle. It will be appreciated that in certain continuous processing operations, two opposing ends of the shaped abrasive particles may be cut surfaces.

In one embodiment, sectioning can be conducted in a particular manner to control one or more angles of one or more end surfaces of the bodies of the precursor shaped abrasive particles and the finally-formed shaped abrasive particles. In one embodiment, sectioning includes simultaneous sectioning of the green body during forming of the green body. In still another non-limiting embodiment, sectioning can include continuous and simultaneous sectioning of portions of the green body during extrusion of the green bodies through the one ormore openings131 of thedie132. For example, one ormore sectioning devices133 may be continuously moving and sectioning extruded green bodies to form precursor shaped abrasive particles, while on another portion of the die apart from the sectioningdevices133, new green bodies are being formed by extruding themixture113 through the one ormore openings131. In another non-limiting embodiment, themixture113 can be continuously extruded while the one ormore sectioning devices133 are sectioning the green bodies at or near thesurface138 of thedie132.

In one optional embodiment, the process may include treating at least one surface of the green body after forming and before sectioning. In certain instances, it may be suitable to treat at least a portion of the green bodies to improve the sectioning operation, which may also limit deformation of the green bodies during sectioning. In one embodiment, treating can include forming of an additive on at least one surface of the green body, forming a coating on at least a portion of the green body, wrapping at least a portion of the green body, changing the temperature of the green body or any combination thereof. In one aspect, treating may include altering the mechanical or chemical nature of at least a portion of the green body to facilitate improved sectioning. In still another non-limiting embodiment, treating may include altering at least a surface of the green body to facilitate improved sectioning. According to one particular embodiment, treating can include stiffening of the green body through a chemical, mechanical or physical change of at least a portion of the green body, which may serve to limit deformation of the body during sectioning. For example, in some instances, a coating may be applied to the surface of the green bodies prior to sectioning. The coating would preferably be removed (e.g., volatilized) during later processing. In another instance, the green body can be rapidly cooled to facilitate stiffening of the gel prior to sectioning.

In still another aspect, treating may also include treating of the one ormore sectioning devices133 to improve sectioning by minimizing distortion of the green body during sectioning. For example, in one particular embodiment, sectioning may include addition of at least one sectioning additive to the sectioning mechanism to minimize distortion of the green body during sectioning. A sectioning additive may include for example, a lubricant on the surface of the one or more sectioning devices that may assist with clean and smooth sectioning of the green body.

FIG.1C includes an illustration of a portion of a system for forming shaped abrasive particles according to an embodiment. Specifically, thesystem180 can include adie132 and at least onesectioning devices133 that may facilitate formation of shaped abrasive particles having one or more features of the embodiments herein. In the illustrated embodiment ofFIG.1C, thedie132 can include one ormore openings131 to facilitate extrusion of the mixture therethrough and facilitate formation of green bodies that can be sectioned by one ormore sectioning devices133. Themixture113 can be extruded through the one ormore openings131 in thedirection134. In one particular embodiment, as illustrated inFIG.1C, the one ormore openings131 can have aparticular opening axis146 that is angled relative to amajor surface axis145 where the one ormore openings131 intersect themajor surface145.

According to one embodiment, the smallest angle between the openingaxis146 andmajor surface axis145 can be anextrusion angle147. In some instances, theextrusion angle147 can be at least 5 degrees, such as at least 8 degrees or at least 10 degrees or at least 15 degrees or at least 20 degrees or at least 25 degrees or at least 30 degrees or at least 35 degrees or at least 40 degrees or at least 45 degrees. Still, in another non-limiting embodiment, theextrusion angle146 may be not greater than 85 degrees, such as not greater than 80 degrees or not greater than 70 degrees or not greater than 60 degrees or not greater than 50 degrees or not greater than 40 degrees or not greater than 30 degrees. It will be appreciated that theextrusion angle147 can be within a range including any of the minimum and maximum values noted above.

According to one embodiment, the smallest angle between the openingaxis146 and theleading edge139 of the one ormore sectioning devices133 can be a sectioningangle148. In some instances, the sectioningangle148 can be at least 5 degrees, such as at least 8 degrees or at least 10 degrees or at least 15 degrees or at least 20 degrees or at least 25 degrees or at least 30 degrees or at least 35 degrees or at least 40 degrees or at least 45 degrees. Still, in another non-limiting embodiment, the sectioningangle148 may be not greater than 85 degrees, such as not greater than 80 degrees or not greater than 70 degrees or not greater than 60 degrees or not greater than 50 degrees or not greater than 40 degrees or not greater than 30 degrees. It will be appreciated that the sectioningangle148 can be within a range including any of the minimum and maximum values noted above. Theextrusion angle147 and/or sectioningangle148 may impact one or more features of the shaped abrasive particles according to embodiments herein.

According to another embodiment, themixture113 can be formed into a green body as it exits the one ormore openings131. The portion of themixture113 extending from the one or moredie openings131 can be a green body having a cross-sectional shape substantially similar to the cross-sectional shape of the one or moredie openings131. In one particular aspect, the green body can be sectioned by asectioning device133 to form a precursor shaped abrasive particle. Thesectioning device133 may be one or more devices, such as blades or other objects suitable for separating the green body from themixture113. Other suitable devices may include sectioning devices using sectioning mediums that are ejected from the sectioning device and may include a gas and/or a liquid. The separation may be at or near themajor surface138 of thedie132. In the illustrated embodiment ofFIG.1C, thesectioning device133 may be coupled to an actuation portion that is configured to move the one ormore sectioning devices133 relative to themajor surface138 of thedie132 and facilitate continuous sectioning of the green bodies to form precursor shaped abrasive particles.

According to one aspect, sectioning can be conducted in a plane non-perpendicular to theopening axis135, which in the illustrated embodiment ofFIG.1C. In another embodiment, sectioning can be conducted in a plane that is non-perpendicular to the longitudinal axis of the green body as it is extruded from the one ormore openings131 of thedie132. As illustrated in the embodiment ofFIG.1C, theleading edge139 of the one ormore sectioning devices133, which his configured to conduct sectioning of the green body, defines a plane that is non-perpendicular to theprimary extrusion axis140 and a longitudinal axis of the green body.

According to one aspect, sectioning can create at least one end surface of the precursor shaped abrasive particle and finally-formed shaped abrasive particle that is a cut surface. In one non-limiting embodiment, the cut surface can be at an end of a body of a precursor shaped abrasive particle or shaped abrasive particle. It will be appreciated that in certain continuous processing operations, two opposing ends of the shaped abrasive particles may be cut surfaces.

In one embodiment, sectioning can be conducted in a particular manner to control one or more angles of one or more end surfaces of the bodies of the precursor shaped abrasive particles and the finally-formed shaped abrasive particles. In one embodiment, sectioning may include simultaneous sectioning of the green body during forming of the green body. In still another non-limiting embodiment, sectioning can include continuous and simultaneous sectioning of portions of the green body during extrusion of the green bodies through the one ormore openings131 of thedie132. For example, one ormore sectioning devices133 may be continuously moving and sectioning extruded green bodies to form precursor shaped abrasive particles, while on another portion of the die132 apart from the sectioningdevices133, new green bodies are being formed by extruding themixture113 through the one ormore openings131. In another non-limiting embodiment, themixture113 can be continuously extruded while the one ormore sectioning devices133 are sectioning the green bodies at or near thesurface138 of thedie132.

In one embodiment, the sectioningdevices133 may be angled with respect to themajor surface138. Specifically, the sectioningdevices133 can be angled and rotated in thedirection148, such that theleading edge139 first contacts the green bodies extending from the one ormore openings131 to facilitate sectioning. Such a configuration can avoid contact of the green bodies with other portions of thesectioning devices133 that may otherwise cause distortion of the green bodies. Movement of thesectioning devices133 can be continuous or intermittent depending upon the speed of extrusion and the desired features of the shaped abrasive particles. Without wishing to be tied to a particular theory, control of process elements in combination with the orientation of the openings relative to the major surface and one or more sectioning devices may facilitate formation of shaped abrasive particles having certain features of the embodiments herein.

It will be appreciated that the process of using the system ofFIG.1C can include any of the processes of other embodiments herein. For example, the process may include an optional treating process, which can include treating at least one surface of the green body after forming and before sectioning. In certain instances, it may be suitable to treat at least a portion of the green bodies to improve the sectioning operation, which may also limit deformation of the green bodies during sectioning. Treating may include, but is not limited to, forming of an additive on at least one surface of the green body, forming a coating on at least a portion of the green body, wrapping at least a portion of the green body, changing the temperature of the green body or any combination thereof.

It will also be appreciated that the precursor shaped abrasive particles formed through the systems and processes described in conjunction with the embodiments ofFIGS.1B-1C can undergo further processing. Such further processing can include any of the processes described herein, including for example, but not limited to doping, calcining, impregnating, drying, sintering, or any combination thereof.

FIGS.2A and2B illustrate a plurality of shaped abrasive particles according to embodiments herein. In particular, the particles ofFIGS.2A and2B can be made through an extrusion and sectioning process, wherein the sectioning process is conducted at a particular angle. The particles ofFIG.2A were formed through a continuous extrusion and sectioning process using a system substantially similar to the system ofFIG.1B and having an extrusion angle of approximately 15 degrees. The particles ofFIG.2B were made via extrusion and sectioning with an extrusion angle of approximately 45 degrees.

Referring now toFIGS.2C and2D, certain features of the shaped abrasive particles of the embodiments herein are described. The features of the embodiments herein are described in the context of finally-formed shaped abrasive particles, but it will be appreciated that the precursor shaped abrasive particles can have any one or more combinations of features described in any of the embodiments herein.

According to one non-limiting embodiment, the plurality of abrasive particles can include a blend of different types of abrasive particles. A blend can include a first portion of abrasive particles and a second portion of abrasive particles. The shaped abrasive particles of the embodiments herein can be present in the first portion, the second portion, or both the first portion and second portion. In one instance, the first portion or the second portion may include only shaped abrasive particles. According to one embodiment, the blend can include a first portion of abrasive particles of a first type and a second portion of abrasive particles of a second type, wherein the first type and second type are different from each other based on at least one abrasive characteristic selected from the group of average grain size, average particle size, friability, toughness, hardness, two-dimensional shape, three-dimensional shape, any of the features described in the embodiments herein, or any combination thereof.

In one non-limiting aspect, the plurality of abrasive particles can include at least 10 grams of abrasive particles, such as at least 100 grams abrasive particles, at least 500 grams of abrasive particles, at least 1 kg of abrasive particles or at least 10 kg of abrasive particles.

In another aspect, the plurality of abrasive particles may include at least 10 abrasive particles, such as at least 20 abrasive particles or at least 30 abrasive particles or at least 50 abrasive particles or at least 100 abrasive particles or at least 500 abrasive particles. It will be appreciated that the number of abrasive particles of the in the plurality of abrasive particles may be within a range of at least 10 abrasive particles to not greater than 100,000 abrasive particles, such as within a range of at least 10 abrasive particles to not greater than 1000 abrasive particles or within range of at least 20 abrasive particles are not greater than 100 abrasive particles.

In still another aspect, the plurality of abrasive particles may include at least a portion, and in some cases, all of the abrasive particles included in a fixed abrasive article, such as, a coated abrasive article. In another embodiment, the plurality of abrasive particles may include all of the abrasive particles in a plurality of fixed abrasive articles.

Referring to one embodiment, the shaped abrasive particles of the embodiments herein may include extruded shaped abrasive particles. The extruded shaped abrasive particles may be formed through an extrusion process. In some embodiments, the extrusion process can create certain features. In one non-limiting embodiment, referring to the shapedabrasive particle200 ofFIG.2C and the shapedabrasive particle250 ofFIG.2D, thebody201 can include side surfaces221,222, and223. It will be appreciated that thebody201 can include a fourth side surface, which is not shown, and can be opposite and substantially parallel to theside surface222. Thebody201 can further include end surfaces225 and226. In one particular aspect, the side surfaces221-223 can extend extending between the end surfaces225 and226. In a more particular embodiment, the side surfaces221-223 can abut the end surfaces225 and226. In yet another embodiment, the side surfaces221-223 can have a greater surface area as compared to a total surface area of the end surfaces225 and226.

According to one particular embodiment, the shapedabrasive particles200 and250 may havestriations271, which may be formed during processing on certain surfaces. For example, in one embodiment, thestriations271 can be formed on at least one side surface221-223. In another embodiment thestriations271 may be present on at least a portion of all of the side surfaces221-223. In another non-limiting embodiment, thestriations271 may extend in a direction of the length (L) of thebody201. In still another embodiment, thestriations271 may extend over a majority of the surface area of at least one or more side surfaces221-223. According to one particular embodiment, thestriations271 extend over a majority of the surface area of all of the side surfaces221-223.

In another embodiment, the end surfaces225 and226 can have different surface features as compared to the side surfaces221-223. For example, in one non-limiting embodiment, the end surfaces225 and226 may have fewer striations as compared to the side surfaces221-223. In a more particular embodiment, at least one of the end surfaces225 and226 may be substantially free ofstriations271, and more particularly, may have nostriations271. Still, in another embodiment, both ends surfaces may be substantially free ofstriations271, and more particularly, both end surfaces can have nostriations271.

According to another aspect, at least one of the end surfaces225 and226 may be cut surfaces formed from a sectioning operation. In one embodiment, both of the end surfaces225 and226 may be cut surfaces. For example,FIG.2E includes an image of an end surface of a shaped abrasive particles like that illustrated inFIG.2C.FIG.2F includes an image of an end surface of a shaped abrasive particles like that illustrated inFIG.2D. Notably, as illustrated, the shaped abrasive particle ofFIG.2F had a rectangular cross-sectional shape, such that the length was greater than the width and the width was greater than the thickness.

In one non-limiting embodiment, at least one of the end surfaces225 and226 can have a different surface contour as compared to at least one of the side surfaces221-223. In one aspect, at least one of the end surfaces225 and226 can have a different surface roughness (Ra) as compared to a surface roughness of at least one side surface221-223. For one particular embodiment, at least one of the end surfaces225 and226 may have an average surface roughness (Ra1) that can be different than an average surface roughness (Ra2) of at least one of the side surfaces221-223. In another embodiment, Ra1 may be less than Ra2. In another non-limiting embodiment, Ra1 may be at least 10% less than Ra2 as measured according to Ra1<[Ra2−(Ra2×0.10)], such as at least 15% less or at least 20% less or at least 25% less than Ra2.

It will be appreciated that in another embodiment, both of the end surfaces225 and226 can have an average surface roughness that is less than a surface roughness of any of the side surfaces221-223. In still another aspect, both of the end surfaces225 and226 can have an average surface roughness that is less than the average surface roughness of all of the side surfaces221-223.

In another embodiment, thebody201 may haveend surfaces225 and226 that can be formed with minimal deformation. For example, the end surfaces225 and226 may be substantially parallel to each other. In one aspect, the end surfaces225 and226 may have a parallelism as measured by the value of an angle at the intersection of theline segments231 and232. Theline segments231 and232 are lines drawn on the end surfaces225 and226, respectively as viewed in cross section. The angle of intersection of theline segments231 and232 is based on an assumption that the line segments represent radial axes extending from a center of the circle, and the angle of intersection is the central angle between theline segments231. In one embodiment, the angle of intersection can be not greater than 10 degrees, such as not greater than 8 degrees or not greater than 6 degrees or not greater than 4 degrees or not greater than 3 degrees or not greater than 2 degrees or not greater than 1 degree or not greater than 0.1 degree or not greater than 0.01 degree. In at least one embodiment, the angel of intersection, which can define the parallelism can be at least 0.000001 degrees, such as at least 0.00001 degrees. It will be appreciated that the angle of intersection can be within a range including any of the minimum and maximum values noted above.

In one embodiment, at least oneend surface225, such as afirst end surface225, can be joined to at least one side surface, such as afirst side surface223, at a firstobtuse angle233. In another embodiment, thefirst end surface225 can be joined to a second side surface, such asside surface221 at a firstacute angle234. In one particular embodiment, thefirst side surface223 andsecond side surface221 can be opposite each other across the width (W) of thebody201. According to another embodiment, theside surface223 may be substantially parallel to theside surface221. For still another embodiment, theside surface223 can be separate from theside surface221 by at least one interveningside surface222.

In another aspect, at least oneend surface225 or226 can be angled with respect to an abutting side surfaces in a non-perpendicular manner Without wishing to be tied to a particular theory, the formation of non-perpendicular angles between the end surfaces225 and226 side surfaces221-223 may facilitate improved performance of the shaped abrasive particles and corresponding fixed abrasive articles using such shaped abrasive particles.

It will also be understood, that in another embodiment from a perpendicular plane defined by the length (L) and thickness of thebody201, theend surface225 can have an obtuse angle and acute angle betweenside surface222 and a side surface opposite and generally parallel to theside surface222. Still, in another embodiment, the firstobtuse angle233 andfirst actuate angle234 may only be visible in view in the plane of the length (L) and width (W) of thebody201.

According to one embodiment, the firstacute angle234 can have a particular angle that may result from particular forming processes, may also facilitate improved performance of the shaped abrasive particles, and may facilitate improved performance of fixed abrasives incorporating such shaped abrasive particles. In one aspect, the firstacute angle234 can be at least 5 degrees, such as at least 8 degrees or at least 10 degrees or at least 15 degrees or at least 20 degrees or at least 25 degrees or at least 30 degrees or at least 35 degrees or at least 40 degrees or at least 45 degrees. In another non-limiting embodiment, the firstacute angle234 may be not greater than 85 degrees, such as not greater than 80 degrees or not greater than 70 degrees or not greater than 60 degrees or not greater than 50 degrees or not greater than 40 degrees or not greater than 30 degrees. It will be appreciated that the firstacute angle234 can have a value within a range including any of the minimum and maximum values noted above.

According to another aspect, the firstobtuse angle233 can have a particular angle that may result from particular forming processes, may also facilitate improved performance of the shaped abrasive particles, and may facilitate improved performance of fixed abrasives incorporating such shaped abrasive particles. In one aspect, the firstobtuse angle233 can be at least 95 degrees, such as at least 100 degrees or at least 110 degrees or at least 120 degrees or at least 130 degrees or at least 140 degrees or at least 150 degrees or at least 160 degrees. In another non-limiting embodiment, the firstobtuse angle233 may be not greater than 175 degrees, such as not greater than 170 degrees or not greater than 160 degrees or not greater than 150 degrees or not greater than 140 degrees or not greater than 130 degrees. It will be appreciated that the firstobtuse angle233 can have a value within a range including any of the minimum and maximum values noted above.

In certain instances, the firstobtuse angle233 andfirst actuate angle234 may have a particular relationship. For example, in one embodiment, the firstobtuse angle233 andfirst actuate angle234 may be substantially supplementary angles, wherein the sum of the angles is 180 degrees (plus or minus 10 degrees). In a more particular embodiment, the firstobtuse angle233 andfirst actuate angle234 may be pure supplementary angles, wherein the sum of the angles is exactly 180 degrees.

In another embodiment, thebody201 can have asecond end surface226 that can be displaced from thefirst end surface225 across the length (L) of thebody201. In a particular aspect, thesecond end surface226 can be joined to thefirst side surface223 at a secondobtuse angle235. In another non-limiting embodiment, thebody201 may have a secondacute angle236 between thesecond side surface226 and thesecond side surface221.

According to one embodiment, the secondacute angle236 can have a particular angle that may result from particular forming processes, may also facilitate improved performance of the shaped abrasive particles, and may facilitate improved performance of fixed abrasives incorporating such shaped abrasive particles. In one aspect, the secondacute angle236 can be at least 5 degrees, such as at least 8 degrees or at least 10 degrees or at least 15 degrees or at least 20 degrees or at least 25 degrees or at least 30 degrees or at least 35 degrees or at least 40 degrees or at least 45 degrees. In another non-limiting embodiment, the secondacute angle236 may be not greater than 85 degrees, such as not greater than 80 degrees or not greater than 70 degrees or not greater than 60 degrees or not greater than 50 degrees or not greater than 40 degrees or not greater than 30 degrees. It will be appreciated that the secondacute angle236 can have a value within a range including any of the minimum and maximum values noted above.

According to another aspect, the secondobtuse angle235 can have a particular angle that may result from particular forming processes, may also facilitate improved performance of the shaped abrasive particles, and may facilitate improved performance of fixed abrasives incorporating such shaped abrasive particles. In one aspect, the secondobtuse angle235 can be at least 95 degrees, such as at least 100 degrees or at least 110 degrees or at least 120 degrees or at least 130 degrees or at least 140 degrees or at least 150 degrees or at least 160 degrees. In another non-limiting embodiment, the secondobtuse angle235 may be not greater than 175 degrees, such as not greater than 170 degrees or not greater than 160 degrees or not greater than 150 degrees or not greater than 140 degrees or not greater than 130 degrees. It will be appreciated that the secondobtuse angle235 can have a value within a range including any of the minimum and maximum values noted above.

In some aspects, the angles of thebody201 may have particular relationships to each other. For example, in one embodiment, the firstobtuse angle233 and secondacute angle236 may be substantially supplementary angles, wherein the sum of the angles is 180 degrees (plus or minus 10 degrees). In a more particular embodiment, the firstobtuse angle233 and secondacute angle236 may be pure supplementary angles, wherein the sum of the angles is exactly 180 degrees.

In another non-limiting embodiment, the firstacute angle234 and secondobtuse angle235 may be substantially supplementary angles, wherein the sum of the angles is 180 degrees (plus or minus 10 degrees). In a more particular embodiment, the firstacute angle234 and secondobtuse angle235 may be pure supplementary angles, wherein the sum of the angles is exactly 180 degrees.

In another non-limiting embodiment, the firstacute angle234 and secondacute angle236 may be substantially complementary angles, wherein the sum of the angles is 90 degrees (plus or minus 10 degrees). In a more particular embodiment, the firstacute angle234 and secondacute angle236 may be pure complementary angles, wherein the sum of the angles is exactly 90 degrees.

In another non-limiting embodiment, the firstacute angle234 and secondacute angle236 may be substantially complementary angles, wherein the sum of the angles is 90 degrees (plus or minus 10 degrees). In a more particular embodiment, the firstacute angle234 and secondacute angle236 may be pure complementary angles, wherein the sum of the angles is exactly 90 degrees.

In one aspect, the firstacute angle234 and secondacute angle236 may have a particular relationship. For example, in one non-limiting embodiment, the first acute angle234 (Aa1) may have a value that is not more than 20% different as compared to the value of the second acute angle236 (Aa2). That is, for example, [Aa1/Aa2]×100%, when Aa1 is less than Aa2 or [Aa2/Aa1]×100% when Aa2 is less than Aa1. In a more particular embodiment, the firstacute angle234 can be no more than 18% different from the value of the secondacute angle236, such as not more than 16% different or not more than 14% different or not more than 12% different or not more than 10% different or not more than 8% different or not more than 6% different or not more than 4% different or not more than 2% different from the value of the secondacute angle236.

In yet another aspect, the firstobtuse angle233 and secondobtuse angle235 may have a particular relationship. For example, in one non-limiting embodiment, the first obtuse angle233 (Ao1) may have a value that is not more than 20% different as compared to the value of the second obtuse angle235 (Ao2). That is, for example, [Ao1/Ao2]×100%, when Ao1 is less than Ao2 or [Ao2/Ao1]×100% when Ao2 is less than Ao1. In a more particular embodiment, the firstobtuse angle233 can be no more than 18% different from the value of the secondobtuse angle235, such as not more than 16% different or not more than 14% different or not more than 12% different or not more than 10% different or not more than 8% different or not more than 6% different or not more than 4% different or not more than 2% different from the value of the secondobtuse angle235.

FIG.2C includes an image of a shaped abrasive particle in a plane defined by a length and width of thebody201.FIG.2D includes an image of a shaped abrasive particle in a plane defined by a length and width of thebody201.

As illustrated in the non-limiting embodiments ofFIGS.2C-2D, the shapedabrasive particles200 and250 may include abody201 having a length (L) a width (W), and a thickness (not-illustrated). In one embodiment, the length can be greater than the width. In another embodiment, the length can be greater than the thickness. In still another embodiment, the width may be greater than, equal to or less than the thickness. Unless otherwise stated, reference to any dimensions herein is understood to be reference to an average value from a suitable sample size of measurements and/or particles. For example, reference to the length includes an average length measured as close as possible to the mid-point of thebody201 along the longitudinal axis (L). The width can be measured in a direction perpendicular to the longitudinal axis (L) in the plane of the length and width. The width can be measured as close as possible to the midpoint of thebody201, which can be assumed to be the midpoint between the points where the longitudinal axis (L) intersects the edges of thebody201. The thickness can be measured in the same manner as the width, but in a plane defined by the length and thickness of the particle, wherein the thickness extends in a direction normal to the plane defined by the length and width of thebody201.

In one non-limiting embodiment, a shaped abrasive particle can include abody201 having afirst tip region210, asecond tip211 and anelongated region212 between the first andsecond tip regions210 and211. The length of thefirst tip region210 andsecond tip region211 as measured as the greatest dimension in the direction of the longitudinal axis (L) can vary depending upon the angles between the end surfaces225 and226 and side surfaces221-223. In one aspect, thebody201 may be substantially linear for a majority of the total length of thebody201. As used herein, the term substantially linear refers to a body that does not deviate from a linear axis more than 20%, such as not greater than 10% or not greater than 5%.

In one embodiment, the first and/orsecond tip regions210 and211 may have a tip region length (measured as the greatest distance in the direction of length in the region defined by a reducing width) that is not greater than 90% of the length of thebody201, such as not greater than 80% or not greater than 70% or not greater than 60% or not greater than 50% or not greater than 40% or not greater than 30% or not greater than 20% or not greater than 10% or not greater than 5% of the total average length of the body. In still another non-limiting embodiment, the first and/orsecond tip regions210 and211 can have a tip region length of at least 5% of the length of thebody201, such as at least 10% or at least 15% or at least 20% or at least 25% or at least 30% or at least 40%. It will be appreciated that the tip region length can be within a range including any of the minimum and maximum percentages noted above.

As noted herein, the shaped abrasive particles of certain embodiments may include andelongated region212 disposed between thefirst tip region210 and thesecond tip region211. More specifically, theelongated region212 can extend between thetip regions210 and211. In one non-limiting embodiment, theelongated region212 can have a substantially constant width. For example, in one embodiment theelongated region212 may have a change in width of not greater than 10% over the length of theelongated region212, such as not greater than 8% or not greater than 5% or not greater than 3%. In at least one embodiment, theelongated region212 may have a change in width of at least 0.5%, such as least 1% or at least 2% over the length of theelongated region212. It will be appreciated that the change in the width of thebody201 in theelongated region212 may be within a range including any of the minimum and maximum percentages noted above.

In another embodiment, theelongated region212 may have a change in thickness of not greater than 10% over the length of theelongated region212, such as not greater than 8% or not greater than 5% or not greater than 3%. In at least one embodiment, theelongated region212 may have a change in thickness of at least 0.5%, such as least 1% or at least 2% over the length of theelongated region212. It will be appreciated that the change in the thickness of thebody201 in theelongated region212 may be within a range including any of the minimum and maximum percentages noted above.

According to one embodiment, thebody201 of the shaped abrasive particles may have a particular primary aspect ratio (length/width) that may result from the disclosed forming process and may also facilitate certain features and/or improved performance. In one aspect, the shaped abrasive particles may have a primary aspect ratio of (length/width) of at least 1.1 or at least 1.2 or at least 1.5 or at least 2 or at least 2.5 or at least 3 or at least 3.5 or at least 4 or at least 4.5 or at least 5 or at least 5.5 or at least 6 or at least 8 or at least 10. In another non-limiting embodiment, thebody201 can have a primary aspect ratio of (length/width) of not greater than 1000 or not greater than 100 or not greater than 50 or not greater than 20 or not greater than 10 or not greater than 5 or not greater than 3 or not greater than 2.5. It will be appreciated that the primary aspect ratio of thebody201 can be with a range including any of the minimum and maximum ratios noted above. Furthermore, it will be appreciated that the primary aspect ratio may represent a primary aspect ratio of a single shaped abrasive particle or an average of a plurality of shaped abrasive particles.

All aspect ratios of the embodiments herein are measured by image processing. A plurality of shaped abrasive particles are mounted and set on a stage for imaging. Imaging may be completed via an optical microscope such as aDSX 700 Olympus at a suitable magnification, such as 2×-8×. After taking a suitable image of a suitable statistically relevant sample size of the particles (e.g., at least 200 particles), the image (RGB color or grayscale) is saved as a representative image of the particle's length and width dimensions. See, for example,FIG.10. The particles are then rotated 90 degrees around the longitudinal axis, such that the dimension of the thickness of each of the particles is visible. An image of the particles is taken and saved as relevant to each particles thickness. The lengths, widths, and thicknesses for each of the particles are measured and the average length, width, and thickness is calculated from the images by image processing software (e.g., ImageJ). For the first picture of the particles in the plane of the length and width, the image is converted to a black and white image via Otsu's method where the white pixels represent the body of the particle. From the black and white image, a best fit ellipse is fit around each of the images of the particles. A best fit ellipse is generated so that the second-moment of the region is preserved. The perpendicular axes of the ellipse (i.e., major axis and minor axis) are used for the length and width, wherein the longer axis represents the length and the shorter axis represents the width or thickness depending upon the plane of the image. The major axis, which defines the length, is defined as the axis on which the foci of the fitted ellipse are presented. The minor axis, which defines the width of the body, is perpendicular to the major axis of the fitted ellipse. The average length and average width are calculated from this image for the plurality of particles.FIGS.9A and9B include images of shaped abrasive particles having a best-fit ellipse. The average thickness of the particles is measured in the same manner using the image of the particles in the dimension of length and thickness. The image is altered to a black and white only image, a best fit ellipse is created around each image of each particle and the thickness is measured as the value of the shortest axis of the ellipse. The average thickness is calculated from all of the measured thickness values. The primary, secondary, and tertiary standard deviations are also calculated from the measured length, width, and thickness values.

In another aspect, the shaped abrasive particles may have a particular primary aspect ratio standard deviation that is distinct from other abrasive particles, particularly elongated shaped abrasive particles that may be formed by particular process, including but not limited to, extrusion. According to one embodiment, thebody201 can have a primary aspect ratio standard deviation [STDEV(length/width)] of not greater than 0.55 or not greater than 0.52 or not greater than 0.50 or not greater than 0.48 or not greater than 0.45 or not greater than 0.42 or not greater than 0.40 or not greater than 0.38 or not greater than 0.35 or not greater than 0.32 or not greater than 0.30 or not greater than 0.28 or not greater than 0.25 or not greater than 0.22 or not greater than 0.20 or not greater than 0.18 or not greater than 0.15. Still, in another non-limiting embodiment, the primary aspect ratio standard deviation [STDEV(length/width)] may be at least 0.01 or at least 0.05 or at least 0.1 or at least 0.15 or at least 0.2 or at least 0.25 or at least 0.30 or at least 0.35 or at least 0.4. It will be appreciated that the primary aspect ratio standard deviation of thebody201 can be with a range including any of the minimum and maximum ratios noted above. Furthermore, it will be appreciated that the primary aspect ratio may represent a primary aspect ratio of a single shaped abrasive particle or an average of a plurality of shaped abrasive particles.

According to one embodiment, thebody201 of the shaped abrasive particles may have a particular secondary aspect ratio (length/thickness) that may result from the disclosed forming process and may also facilitate certain features and/or improved performance. In one non-limiting embodiment, thebody201 can have a secondary aspect ratio of length/thickness that can be at least 1.1 or at least 1.2 or at least 1.5 or at least 2 or at least 2.5 or at least 3 or at least 3.5 or at least 4 or at least 4.5 or at least 5 or at least 5.5 or at least 6 or at least 8 or at least 10. Still, in another non-limiting embodiment, the secondary aspect ratio (length/thickness) may be not greater than 1000 or not greater than 100 or not greater than 50 or not greater than 20 or not greater than 10 or not greater than 5 or not greater than 3 or not greater than 2.5. It will be appreciated the secondary aspect ratio of length/thickness can be with a range including any of the minimum and maximum ratios of above. Furthermore, it will be appreciated that the secondary aspect ratio may represent a secondary aspect ratio of a single shaped abrasive particle or an average of a plurality of shaped abrasive particles.

In another aspect, the shaped abrasive particles may have a particular secondary aspect ratio standard deviation that is distinct from other abrasive particles, particularly elongated shaped abrasive particles that may be formed by particular process, including but not limited to, extrusion. According to one embodiment, thebody201 can have a secondary aspect ratio standard deviation [STDEV(length/thickness)] of not greater than 0.55, such as not greater than 0.52 or not greater than 0.50 or not greater than 0.48 or not greater than 0.45 or not greater than 0.42 or not greater than 0.40 or not greater than 0.38 or not greater than 0.35 or not greater than 0.32 or not greater than 0.30 or not greater than 0.28 or not greater than 0.25 or not greater than 0.22 or not greater than 0.20 or not greater than 0.18 or not greater than 0.15 or not greater than 0.12 or not greater than 0.10. Still, in another non-limiting embodiment, the secondary aspect ratio standard deviation [STDEV(length/thickness)] may be at least 0.01 or at least 0.05 or at least 0.07 or at least 0.1 or at least 0.15 or at least 0.2 or at least 0.25 or at least 0.30 or at least 0.35 or at least 0.4. It will be appreciated that the secondary aspect ratio standard deviation of thebody201 can be with a range including any of the minimum and maximum ratios noted above. Furthermore, it will be appreciated that the secondary aspect ratio may represent a secondary aspect ratio of a single shaped abrasive particle or an average of a plurality of shaped abrasive particles.

According to one embodiment, thebody201 of the shaped abrasive particles may have a particular tertiary aspect ratio (width/thickness) that may result from the disclosed forming process and may also facilitate certain features and/or improved performance. In another embodiment, thebody201 can have a tertiary aspect ratio (width/thickness) of at least 0.5, such as at least 0.6 or at least 0.7 or at least 0.8 or at least 0.9 or at least 1.0 or at least 1.1 or at least 1.2 or at least 1.3 or at least 1.4 or at least 1.5 or at least 2 or at least 2.5 or at least 3 or at least 4. In another non-limiting embodiment, the tertiary aspect ratio (width/thickness) can be not greater than 10, such as not greater than 8 or not greater than 5 or not greater than 3 or not greater than 2 or not greater than 1.5 or not greater than 1.3 or not greater than 1.1. It will be appreciated that the tertiary aspect ratio can be with a range including any of the minimum and maximum ratios noted above. Furthermore, it will be appreciated that the tertiary aspect ratio may represent a tertiary aspect ratio of a single shaped abrasive particle or an average of a plurality of shaped abrasive particles.

In another aspect, the shaped abrasive particles may have a particular tertiary aspect ratio standard deviation that is distinct from other abrasive particles, particularly elongated shaped abrasive particles that may be formed by particular process, including but not limited to, extrusion. According to one embodiment, thebody201 can have a tertiary aspect ratio standard deviation [STDEV(width/thickness)] of not greater than 0.55 or not greater than 0.52 or not greater than 0.50 or not greater than 0.48 or not greater than 0.45 or not greater than 0.42 or not greater than 0.40 or not greater than 0.38 or not greater than 0.35 or not greater than 0.32 or not greater than 0.30 or not greater than 0.28 or not greater than 0.25 or not greater than 0.22 or not greater than 0.20 or not greater than 0.18 or not greater than 0.15 or not greater than 0.12 or not greater than 0.10. Still, in another non-limiting embodiment, the tertiary aspect ratio standard deviation [STDEV(width/thickness)] is at least 0.01 or at least 0.05 or at least 0.07 or at least 0.1 or at least 0.15 or at least 0.2 or at least 0.25 or at least 0.30 or at least 0.35 or at least 0.4. It will be appreciated that the tertiary aspect ratio standard deviation of thebody201 can be with a range including any of the minimum and maximum ratios noted above. Furthermore, it will be appreciated that the tertiary aspect ratio may represent a secondary aspect ratio of a single shaped abrasive particle or an average of a plurality of shaped abrasive particles.

In certain instances, a plurality of abrasive particles may include only shaped abrasive particles or a blend of shaped abrasive particles with particles of a different shape. The plurality of abrasive particles may have particular “batch” features as described in embodiments herein. According to one aspect, the plurality of abrasive particles can have particular batch aspect ratios and batch aspect ratio standard deviations that may result from the processes disclosed herein and may further facilitate improved performance. In one non-limiting embodiment, the plurality of abrasive particles may have a primary batch aspect ratio [B(length/width)] of at least 1.1 or at least 1.2 or at least 1.5 or at least 2 or at least 2.5 or at least 3 or at least 3.5 or at least 4 or at least 4.5 or at least 5 or at least 5.5 or at least 6 or at least 8 or at least 10. In another non-limiting embodiment, the primary batch aspect ratio [B(length/width)] may be not greater than 1000 or not greater than 100 or not greater than 50 or not greater than 20 or not greater than 10 or not greater than 5 or not greater than 3 or not greater than 2.5. It will be appreciated that the primary batch aspect ratio can be with a range including any of the minimum and maximum ratios noted above. The batch aspect ratios and aspect ratio standard deviations are measured in the same manner as provided above with respect to the aspect ratio and aspect ratio standard deviations for the shaped abrasive particles.

In another aspect, the plurality of abrasive particles may have a particular primary batch aspect ratio standard deviation that is distinct from other abrasive particles, particularly elongated shaped abrasive particles that may be formed by particular process, including but not limited to, extrusion. According to one embodiment, the plurality of particles can have a primary batch aspect ratio standard deviation [STDEV-B(length/width)] of not greater than 0.55, such as not greater than 0.52 or not greater than 0.50 or not greater than 0.48 or not greater than 0.45 or not greater than 0.42 or not greater than 0.40 or not greater than 0.38 or not greater than 0.35 or not greater than 0.32 or not greater than 0.30 or not greater than 0.28 or not greater than 0.25 or not greater than 0.22 or not greater than 0.20 or not greater than 0.18 or not greater than 0.15. Still, in another non-limiting embodiment, the primary batch aspect ratio standard deviation [STDEV-B(length/width)] can be at least 0.01 or at least 0.05 or at least 0.1 or at least 0.15 or at least 0.2 or at least 0.25 or at least 0.30 or at least 0.35 or at least 0.4. It will be appreciated that the primary batch aspect ratio standard deviation can be with a range including any of the minimum and maximum ratios noted above.

In one non-limiting embodiment, the plurality of abrasive particles may have a secondary batch aspect ratio [B(length/thickness)] of at least 1.1 or at least 1.2 or at least 1.5 or at least 2 or at least 2.5 or at least 3 or at least 3.5 or at least 4 or at least 4.5 or at least 5 or at least 5.5 or at least 6 or at least 8 or at least 10. In another non-limiting embodiment, the secondary batch aspect ratio [B(length/thickness)] may be not greater than 1000 or not greater than 100 or not greater than 50 or not greater than 20 or not greater than 10 or not greater than 5 or not greater than 3 or not greater than 2.5. It will be appreciated that the secondary batch aspect ratio can be with a range including any of the minimum and maximum ratios noted above.

In another aspect, the plurality of abrasive particles may have a particular secondary batch aspect ratio standard deviation that is distinct from other abrasive particles. According to one embodiment, the plurality of particles can have a secondary batch aspect ratio standard deviation [STDEV-B(length/thickness)] of not greater than 0.55, such as not greater than 0.52 or not greater than 0.50 or not greater than 0.48 or not greater than 0.45 or not greater than 0.42 or not greater than 0.40 or not greater than 0.38 or not greater than 0.35 or not greater than 0.32 or not greater than 0.30 or not greater than 0.28 or not greater than 0.25 or not greater than 0.22 or not greater than 0.20 or not greater than 0.18 or not greater than 0.15 or not greater than 0.12 or not greater than 0.10. Still, in another non-limiting embodiment, the secondary batch aspect ratio standard deviation [STDEV-B(length/thickness)] can be at least 0.01 or at least 0.05 or at least 0.07 or at least 0.1 or at least 0.15 or at least 0.2 or at least 0.25 or at least 0.30 or at least 0.35 or at least 0.4. It will be appreciated that the secondary batch aspect ratio standard deviation can be with a range including any of the minimum and maximum ratios noted above.

In one non-limiting embodiment, the plurality of abrasive particles may have a tertiary batch aspect ratio [B(width/thickness)] of at least 0.5 or at least 0.6 or at least 0.7 or at least 0.8 or at least 0.9 or at least 1.0 or at least 1.1 or at least 1.2 or at least 1.3 or at least 1.4 or at least 1.5 or at least 2 or at least 2.5 or at least 3 or at least 4. In another non-limiting embodiment, the tertiary batch aspect ratio [B(width/thickness)] may be not greater than 10 or not greater than 8 or not greater than 5 or not greater than 3 or not greater than 2 or not greater than 1.5 or not greater than 1.3 or not greater than 1.1. It will be appreciated that the tertiary batch aspect ratio can be with a range including any of the minimum and maximum ratios noted above.

In another aspect, the plurality of abrasive particles may have a particular tertiary batch aspect ratio standard deviation that is distinct from other abrasive particles. According to one embodiment, the plurality of particles can have a tertiary batch aspect ratio standard deviation [STDEV-B(width/thickness)] of not greater than 0.55, such as not greater than 0.52 or not greater than 0.50 or not greater than 0.48 or not greater than 0.45 or not greater than 0.42 or not greater than 0.40 or not greater than 0.38 or not greater than 0.35 or not greater than 0.32 or not greater than 0.30 or not greater than 0.28 or not greater than 0.25 or not greater than 0.22 or not greater than 0.20 or not greater than 0.18 or not greater than 0.15 or not greater than 0.12 or not greater than 0.10. Still, in another non-limiting embodiment, the tertiary batch aspect ratio standard deviation [STDEV-B(width/thickness)] can be at least 0.01 or at least 0.05 or at least 0.07 or at least 0.1 or at least 0.15 or at least 0.2 or at least 0.25 or at least 0.30 or at least 0.35 or at least 0.4. It will be appreciated that the tertiary batch aspect ratio standard deviation can be with a range including any of the minimum and maximum ratios noted above.

The shaped abrasive particles of the embodiments herein can have a body including a crystalline material, and more particularly, a polycrystalline material. Notably, the polycrystalline material can include abrasive grains (i.e., crystallites). In one embodiment, the body of the abrasive particle can be essentially free of an organic material, including for example, a binder. In at least one embodiment, the abrasive particles can consist essentially of a polycrystalline material.

The abrasive grains (i.e., crystallites) contained within thebody201 of the shaped abrasive particles may have an average grain size that is generally not greater than 20 microns, such as not greater than 18 microns or not greater than 16 microns or not greater than 14 microns or not greater than 12 microns or not greater than 10 microns or not greater than 8 micron or not greater than 5 microns or not greater than 2 microns or not greater than 1 micron or not greater than 0.9 microns or not greater than 0.8 microns or not greater than 0.7 microns or even not greater than 0.6 microns or even not greater than 0.2 microns. Still, the average grain size of the abrasive grains contained within thebody201 of the abrasive particles can be at least 0.01 microns, such as at least 0.05 microns or at least 0.06 microns or at least 0.07 microns or at least 0.08 microns or at least 0.09 microns or at least 0.1 microns or at least 0.12 microns or at least 0.15 microns or at least 0.17 microns or at least 0.2 microns or even at least 0.5 microns. It will be appreciated that the abrasive grains can have an average grain size within a range including any of the minimum and maximum values noted above. The average grain size can be calculated using the uncorrected intercept method as known to those of skill in the art.

In accordance with an embodiment, thebody201 of the shaped abrasive particle can have an average particle size, as measured by the largest dimension measurable on the body (i.e., the length), of at least 100 microns. In fact, thebody201 of the shaped abrasive particle can have an average particle size of at least 150 microns, such as at least 200 microns or at least 300 microns or at least 400 microns or at least 500 microns or at least 500 microns or at least 600 microns or at least 800 microns or even at least 900 microns. Still, thebody201 of the shaped abrasive particle can have an average particle size that is not greater than 5 mm, such as not greater than 3 mm or not greater than 2 mm or even not greater than 1.5 mm. It will be appreciated that the body of the abrasive particle can have an average particle size within a range including any of the minimum and maximum values noted above.

Particles for use in the abrasives industry are generally graded to a given particle size distribution before use. Such distributions typically have a range of particle sizes, from coarse particles to fine particles. In the abrasive art, this range is sometimes referred to as a “coarse”, “control”, and “fine” fractions. Abrasive particles graded according to abrasive industry accepted grading standards specify the particle size distribution for each nominal grade within numerical limits. Such industry accepted grading standards (i.e., abrasive industry specified nominal grade) include those known as the American National Standards Institute, Inc. (ANSI) standards, Federation of European Producers of Abrasive Products (FEPA) standards, and Japanese Industrial Standard (JIS) standards. ANSI grade designations (i.e., specified nominal grades) include: ANSI 4, ANSI 6, ANSI 8, ANSI 16, ANSI 24, ANSI 36,ANSI 40,ANSI 50,ANSI 60,ANSI 80,ANSI 100, ANSI 120, ANSI 150,ANSI 180, ANSI 220, ANSI 240, ANSI 280, ANSI 320, ANSI 360, ANSI 400, andANSI 600. FEPA grade designations include P8, P12, P16, P24, P36, P40, P50, P60, P80, P100, P120, P150,PI 80, P220, P320, P400, P500, P600, P800, P1000, and P1000. JIS grade designations include JIS8, JIS12, JIS 16, JIS24, JIS36, JIS46, JIS54, JIS60, JIS80,JIS 100, JIS150, JIS180, JIS220, JIS240, JIS280, JIS320, JIS360, JIS400, JIS600, JIS800, JIS 1000, JIS 1500, JIS2500, JIS4000, JIS6000, JIS8000, and JIS10,000. Alternatively, the abrasive particles can be graded to a nominal screened grade using U.S.A. Standard Test Sieves conforming to ASTM E-11 “Standard Specification for Wire Cloth and Sieves for Testing Purposes.” ASTM E-11 prescribes the requirements for the design and construction of testing sieves using a medium of woven wire cloth mounted in a frame for the classification of materials according to a designated particle size. A typical designation may be represented as −18+20 meaning that the particles pass through a test sieve meeting ASTM E-11 specifications for the number 18 sieve and are retained on a test sieve meeting ASTM E-11 specifications for thenumber 20 sieve. In various embodiments, the particulate material can have a nominal screened grade comprising: −18+20, −20/+25, −25+30, −30+35, −35+40, −40+45, −45+50, −50+60, −60+70, −70/+80, −80+100, −100+120, −120+140, −140+170, −170+200, −200+230, −230+270, −270+325, −325+400, −400+450, −450+500, or −500+635. Alternatively, a custom mesh size could be used such as −90+100. The body of the particulate material may be in the form of a shaped abrasive particle, as described in more detail herein.

Some suitable materials for use in thebody201 of the shaped abrasive particles can include a ceramic material, including but not limited to, nitrides, oxides, carbides, borides, oxynitrides, oxyborides, oxycarbides, carbon-based materials, diamond, naturally occurring minerals, rare-earth-containing materials, natural minerals, synthetic materials, or any combination thereof. In particular instances, the shaped abrasive particles can include an oxide compound, such as aluminum oxide, zirconium oxide, titanium oxide, yttrium oxide, chromium oxide, strontium oxide, silicon oxide, magnesium oxide, rare-earth oxides, or any combination thereof.

In one particular embodiment, thebody201 can include at least 95 wt % alumina for the total weight of thebody201. Still, in certain instances, the body can include not greater than 99.5 wt % alumina for the total weight of the body. In at least one embodiment, thebody201 can consist essentially of alumina, and more particularly, consist essentially of alpha alumina. In certain instances, thebody201 may be formed such that it includes not greater than about 1 wt % of any low-temperature alumina phases. As used herein, low temperature alumina phases can include transition phase aluminas, bauxites or hydrated alumina, including for example gibbsite, boehmite, diaspore, and mixtures containing such compounds and minerals. Certain low temperature alumina materials may also include some content of iron oxide. Moreover, low temperature alumina phases may include other minerals, such as goethite, hematite, kaolinite, and anastase.

Moreover, in particular instances, thebody201 of the shaped abrasive particles can be formed from a seeded sol-gel. In at least one embodiment, the body of any of the abrasive particles of the embodiments herein may be essentially free of iron, rare-earth oxides, and a combination thereof. Reference herein to a body having a certain features (e.g., composition) will also be understood to refer to a batch of abrasive particles that can have the same feature (e.g., composition).

In accordance with certain embodiments, certain shaped abrasive particles can be compositional composites, such that at least two different types of grains are contained within the body of the abrasive particle. It will be appreciated that different types of grains are crystallite grains having different compositions with regard to each other. For example, the body of the abrasive particle can be formed such that it includes at least two different types of grains, wherein the types of grains are selected from the group of nitrides, oxides, carbides, borides, oxynitrides, oxyborides, oxycarbides, carbon-based materials, diamond, naturally occurring minerals, rare-earth-containing materials, natural minerals, synthetic materials, and a combination thereof.

Thebody201 of the shaped abrasive particles may include additives, such as dopants, which may be in the form of elements or compounds (e.g., oxides). Certain suitable additives can include any of the materials described herein. The body of an abrasive article may include a specific content of one or more additives (e.g., dopant). For example, the body may include not greater than about 30 wt % additives for the total weight of the body. In still other embodiments, the amount of additives may be less, such as not greater than about 25 wt % or not greater than about 20 wt % or not greater than about 18 wt % or not greater than about 15 wt % or not greater than about 12 wt % or not greater than about 10 wt % or not greater than about 8 wt % or not greater than 5 wt % or not greater than 2 wt %. Still, the amount of additives can be at least about 0.5 wt % for a total weight of the body, such as at least about 1 wt %, at least about 2 wt % or at least about 3 wt % or at least about 4 wt % or at least about 5 wt % or at least about 8 wt % or even at least about 10 wt %. It will be appreciated that the amount of additive within the body may be within a range including any of the minimum and maximum percentages noted above.

The body of the abrasive particle may be particularly dense. For example, the body may have a density of at least about 95% theoretical density, such as at least about 96% or at least 97% or at least 98% or at least 99% theoretical density.

The shaped abrasive particles of the embodiments herein are a particular type of shaped abrasive particle. Shaped abrasive particles can be formed such that each particle has substantially the same arrangement of surfaces and edges relative to each other. For example, a group of shaped abrasive particles generally have the same arrangement and orientation and or two-dimensional shape of the surfaces and edges relative to each other. As such, the shaped abrasive particles have a relatively high shape fidelity and consistency in the arrangement of the surfaces and edges relative to each other. Moreover, constant height (or thickness) abrasive particles (CHAPs) can also be formed through particular processes that facilitate formation of thin-shaped bodies that can have irregular two-dimensional shapes when viewing the major surface top-down or the particle in the plane of the length and width. CHAPs can have less shape fidelity than shaped abrasive particles, but can have substantially planar and parallel major surfaces separated by a side surface.

By contrast, non-shaped particles can be formed through different processes and have different shape attributes compared to shaped abrasive particles and CHAPs. For example, non-shaped particles are typically formed by a comminution process wherein a mass of material is formed and then crushed and sieved to obtain abrasive particles of a certain size. However, a non-shaped particle will have a generally random arrangement of surfaces and edges, and generally will lack any recognizable two-dimensional or three-dimensional shape in the arrangement of the surfaces and edges. Moreover, non-shaped particles do not necessarily have a consistent shape with respect to each other, and therefore have a significantly lower shape fidelity compared to shaped abrasive particles or CHAPs. The non-shaped particles generally are defined by a random arrangement of surfaces and edges for each particle and with respect to other non-shaped particles.

FIG.3 includes a cross-sectional illustration of a coated abrasive article incorporating the shaped abrasive particles in accordance with an embodiment. As illustrated, the coated abrasive300 can include asubstrate301 and amake coat303 overlying a surface of thesubstrate301. In one particular embodiment, the coated abrasive300 can further include a plurality ofabrasive particles305. The plurality ofabrasive particles305 may include, but need not necessarily include, different types of abrasive particles. For example, the plurality ofabrasive particles305 may include a first type of abrasive particle406 (e.g., shaped abrasive particles), a second type of abrasive particle307 (e.g., unshaped or irregular abrasive particles), and optionally a third type of abrasive particle308 (e.g., diluent abrasive particles), which may have a random shape. The coated abrasive300 may further includesize coat304 overlying and bonded to the plurality ofabrasive particles305 and themake coat303.

In accordance with an embodiment, the plurality of abrasive particles included in the coated abrasive article can include at least a portion of shaped abrasive particles. For example, in one embodiment, at least 5% of the abrasive particles in the plurality of abrasive particles a coated abrasive article can include shaped abrasive particles as calculated based on the number of particles. In other embodiments, the content of shaped abrasive particles can be greater, such as at least 10% or at least 20% or at least 30% or at least 40% or at least 50% or at least 60% or at least 70% or at least 80% or at least 90% or at least 95% or at least 99%. In one embodiment, the plurality of abrasive particles on a coated abrasive can consist entirely of shaped abrasive particles. Still, in one non-limiting embodiment, the plurality of abrasive particles may include not greater than 99% shaped abrasive particles calculated on the number of particles in the plurality, such as not greater than 95% or not greater than 90% or not greater than 80% or not greater than 70% or not greater than 60% or not greater than 50%. It will be appreciated that the percentage of shaped abrasive particles present in the plurality of abrasive particles can be within a range including any of the minimum and maximum values noted above. The above percentages may represent a percentage based on total count of the abrasive particles of weight percent based on the total weight of the plurality of abrasive particles.

According to one embodiment, thesubstrate301 can include an organic material, inorganic material, and a combination thereof. In certain instances, thesubstrate301 can include a woven material. However, thesubstrate301 may be made of a non-woven material. Particularly suitable substrate materials can include organic materials, including polymers, and particularly, polyester, polyurethane, polypropylene, polyimides such as KAPTON from DuPont, paper. Some suitable inorganic materials can include metals, metal alloys, and particularly, foils of copper, aluminum, steel, and a combination thereof.

Themake coat303 can be applied to the surface of thesubstrate301 in a single process, or alternatively, the plurality ofabrasive particles305 can be combined with amake coat303 material and applied as a mixture to the surface of thesubstrate301. Suitable materials of themake coat303 can include organic materials, particularly polymeric materials, including for example, polyesters, epoxy resins, polyurethanes, polyamides, polyacrylates, polymethacrylates, poly vinyl chlorides, polyethylene, polysiloxane, silicones, cellulose acetates, nitrocellulose, natural rubber, starch, shellac, and mixtures thereof. In one embodiment, themake coat303 can include a polyester resin. The coated substrate can then be heated in order to cure the resin and the abrasive particulate material to the substrate. In general, thecoated substrate301 can be heated to a temperature of between about 100° C. to less than about 250° C. during this curing process.

Moreover, it will be appreciated that the coatedabrasive article300 can include one or more types of abrasive particles in the plurality ofabrasive particles305. The different types of abrasive particles can differ from each other in composition, two-dimensional shape, three-dimensional shape, grain size, particle size, hardness, friability, agglomeration, or any combination thereof. In one embodiment, the coatedabrasive article300 can include different amounts of the different types of abrasive particles depending upon the application. It will be appreciated that in some embodiments the coated abrasive may not necessarily include different types of shaped abrasive particles and can consist essentially of a single type of shaped abrasive particle.

According to one particular embodiment, the plurality ofabrasive particles305 may include a limited content of agglomerated particles, and more particularly, a limited content of agglomerated tapered particles. Some agglomerates of shaped abrasive particles may be joined or sinter-bonded to each other. In one aspect, the plurality ofabrasive particles305 may include not greater than 50% of agglomerated particles for a total count of particles in the plurality ofabrasive particles305, such as not greater than 48% or not greater than 46% or not greater than 44% or not greater than 42% or not greater than 40% or not greater than 38% or not greater than 36% or not greater than 34% or not greater than 32% or not greater than 30% or not greater than 28% or not greater than 26% or not greater than 24% or not greater than 22% or not greater than 20% or not greater than 18% or not greater than 16% or not greater than 14% or not greater than 12% or not greater than 10% or not greater than 8% or not greater than 6% or not greater than 4% or not greater than 2%. In one particular embodiment, the plurality ofabrasive particles305 can be free of agglomerated particles, and more particularly, shaped abrasive particles that are joined or sinter-bonded to each other. Notably, in certain conventional fixed abrasive articles including shaped abrasive particles, the fixed abrasive particles may agglomerate in the form of “twins” or “triplets” which are particles that are sintered to each other. The processes herein may facilitate formation of batches of abrasive particles and fixed abrasives including a plurality of abrasive particles having a limited content of agglomerated particles.

Furthermore, in one embodiment, the plurality ofabrasive particles305 may include a limited content of hook-shaped abrasive particles. Hook shaped abrasive particles may include extruded, hook-shaped abrasive particles. Hook-shaped abrasive particles are characterized by at least one end of the body that curls significantly back toward the particle to be characterized as a hook-shape.FIG.4 includes images of various hook-shaped abrasive particles.

Various methods may be used to place the abrasive particles on the backing (i.e., substrate), including for example, but not limited to, projection (e.g., mechanical or electrostatic), gravity feeding, production tools with suitably sized openings to temporarily hold the abrasive particles in a desired orientation until they are transferred to the backing or an adhesive layer, vibration, pick-and-place systems, and the like. Certain methodologies may be more suitable for controlling one or more aspects of the position and/or orientation of the abrasive particles relative to each other and the backing.

According to one particular embodiment, the shaped abrasive particles may have a particular orientation, such as a vertical orientation relative to thesubstrate301. As described in other embodiments herein, the shapedabrasive particles306 can have afirst tip region210 and asecond tip region211 opposite thefirst tip region210 across the length of thebody201. In one aspect, a certain content of shapedabrasive particles306 can be oriented with at least onetip region210 or211 closer to thesubstrate301 than theelongated region212, and particularly with a tilt angle greater than 45 degrees, as described in other embodiments herein. In at least one embodiment, a majority of the shaped abrasive particles can have a vertical orientation, such as at least 60%, such as at least 70% or at least 80% or at least 90% of the shaped abrasive particles.

After sufficiently forming themake coat303 with the plurality ofabrasive particles305 contained therein, thesize coat304 can be formed to overlie and bond the plurality ofabrasive particles305 to thesubstrate301. Thesize coat304 can include an organic material, may be made essentially of a polymeric material, and notably, can use polyesters, epoxy resins, polyurethanes, polyamides, polyacrylates, polymethacrylates, poly vinyl chlorides, polyethylene, polysiloxane, silicones, cellulose acetates, nitrocellulose, natural rubber, starch, shellac, and mixtures thereof.

FIG.5 includes a top-view illustration of a portion of a coated abrasive article according to an embodiment. As illustrated, the coatedabrasive article500 can include abacking501 and a plurality of abrasive particles503 including shapedabrasive particles504,505,506,507, and508 (504-508) overlying thebacking501, and more particularly, coupled to thebacking501. It will be appreciated that the shaped abrasive particles are depicted as circles for ease of reference and not for accuracy of shape. In one embodiment, at least a portion, such as a majority or even all of the plurality of abrasive particles503 can be placed in predetermined positions on thebacking501. According to one embodiment, the plurality of abrasive particles503 can have a predetermined position relative to each other. In a particular embodiment, the plurality of abrasive particles503 may have at least one of a predetermined lateral position, a predetermined longitudinal position, a predetermined radial position, a predetermined rotational orientation, and/or a predetermined tilt angle relative to thebacking501 and relative to each other. In a more particular embodiment, the plurality of abrasive particles503 may have a combination of two or more of a predetermined lateral position, a predetermined longitudinal position, a predetermined radial position, a predetermined rotational orientation or a predetermined tilt angle relative to thebacking501 and relative to each other.

According to a particular embodiment, each of the shaped abrasive particles504-508 may be disposed in a predetermined position on thebacking501. For example, each of the shaped abrasive particles504-508 may have at least one of a predetermined lateral position, a predetermined longitudinal position, a predetermined radial position, and/or a predetermined rotational orientation relative to thebacking501 and relative to each other. In a more particular embodiment, each of the shaped abrasive particles504-508 may have a combination of two or more of a predetermined lateral position, a predetermined longitudinal position, a predetermined radial position, and/or a predetermined rotational orientation relative to thebacking501 and relative to each other.

According to one aspect, the shaped abrasive particles504-508 are disposed on predetermined lateral and longitudinal positions on thebacking501. As illustrated in the non-limiting embodiment ofFIG.5, the shapedabrasive particle504 is disposed at apredetermined position514, the shapedabrasive particle505 is disposed at apredetermined position515, the shapedabrasive particle506 is disposed at apredetermined position516, the shapedabrasive particle507 is disposed at apredetermined position517, and the shapedabrasive particle508 is disposed at apredetermined position518. Each of thepredetermined positions514,515,516,517, and518 (514-518) define a position on the backing relative to the longitudinal andlateral axes580 and581, respectively. Thelongitudinal axis580 can extend along and define a length of thebacking501 and alateral axis581 can extend along and define a width of abacking501. Thelateral axis581 can be perpendicular to thelongitudinal axis580 in the plane of thebacking501. It will be appreciated that the spacing between adjacent abrasive particles (e.g., shaped abrasive particles504-508) can be modified depending upon the content and desired distribution of the abrasive particles. Moreover, it will also be appreciated that such predetermined positions are equally applicable to ellipsoidal backings, which do not necessarily have longitudinal and lateral axes, but have radial axes extending through 360 degrees and distances from a center.

In accordance with another embodiment, the plurality of abrasive particles503 on a coated abrasive article can be arranged in a predetermined distribution relative to each other as viewed top-down. A predetermined distribution can be defined by a combination of predetermined positions on a backing that are purposefully selected. In one embodiment, a predetermined distribution can include a pattern, such that the predetermined positions can define a two-dimensional array. In another embodiment, an array may include have short range order defined by a unit of abrasive particles. In yet another aspect, an array may also be a pattern, having long range order including regular and repetitive units linked together, such that the arrangement may be symmetrical and/or predictable. In some instances, an array may have an order that can be predicted by a mathematical formula. It will be appreciated that two-dimensional arrays can be formed in the shape of polygons, ellipsis, ornamental indicia, product indicia, or other designs.

In another aspect, a predetermined distribution can also include a non-shadowing arrangement. For example, a non-shadowing arrangement may include a controlled, non-uniform distribution, a controlled uniform distribution, and a combination thereof. In some non-limiting instances, a non-shadowing arrangement may include a radial pattern, a spiral pattern, a phyllotactic pattern, an asymmetric pattern, a self-avoiding random distribution, a self-avoiding random distribution and a combination thereof. In one embodiment, a non-shadowing arrangement may include a particular arrangement of abrasive particles (i.e., shaped abrasive particles and/or diluent particles) relative to each other, wherein the degree of overlap of the abrasive particles during an initial phase of a material removal operation is not greater than about 25%, such as not greater than about 20%, not greater than about 15%, not greater than about 10%, or even not greater than about 5%. In particular instances, a non-shadowing arrangement may include a distribution of abrasive particles, wherein upon engagement with a workpiece during an initial stage of a material removal operation, a portion (e.g., a minority of all shaped abrasive particles on the backing, a majority of all shaped abrasive particles on the backing, or even essentially all) of the abrasive particles engage a different region of the surface of the workpiece. A non-shadowing arrangement may utilize a particular distribution of shaped abrasive particles relative to each other and relative to a grinding direction and/or one or more axes of the backing.

In one embodiment, the predetermined distribution can be partially, substantially, or fully asymmetric. For example, according to one embodiment, the predetermined distribution can overlie the entire abrasive article, can cover substantially the entire abrasive article (i.e. greater than 50% but less than 100%), overlie multiple portions of the abrasive article, or overlie a fraction of the abrasive article (i.e, less than 50% of the surface area of the article). As used herein, “a phyllotactic pattern” means a pattern related to phyllotaxis. Phyllotaxis is the arrangement of lateral organs such as leaves, flowers, scales, florets, and seeds in many kinds of plants. Many phyllotactic patterns are marked by the naturally occurring phenomenon of conspicuous patterns having arcs, spirals, and whorls. The pattern of seeds in the head of a sunflower is an example of this phenomenon.

FIG.6A includes a top-down illustration of a portion of a coated abrasive article according to an embodiment. The coatedabrasive article600 includes abacking601 and a plurality ofabrasive particles602, which may include one or more shaped abrasive particles. In one embodiment, at least a portion of plurality ofabrasive particles602 may have a predetermined rotational orientation, which may be the orientation of an abrasive particle around a Z-axis extending perpendicular to the plane of thebacking601. In one embodiment, theabrasive particle603 overlying thebacking601 in afirst position613 may have a rotational orientation relative to alateral axis681 defining the width of thebacking601. In particular aspects, theabrasive particle603 can have a predetermined rotational orientation defined by arotational angle620. Therotational angle620 can be the smallest angle formed between thelateral plane684 extending through thecenter point621 and a bisectingaxis631 parallel to the reference dimension of the particle (e.g., thickness or width) also extending through thecenter point621 as viewed top-down. According to one embodiment, theabrasive particle602 can have a predetermined rotational orientation defined by therotational angle620 which is measured as the smallest angle between a bisectingaxis631 and the lateral plane184. In accordance with an embodiment, therotational angle201 can be 0 degrees, such as at least about 2 degrees, at least about 5 degrees, at least about 10 degrees, at least about 15 degrees, at least about 20 degrees, at least about 25 degrees, at least about 30 degrees, at least about 35 degrees, at least about 40 degrees, at least about 45 degrees, at least about 50 degrees, at least about 55 degrees, at least about 60 degrees, at least about 70 degrees, at least about 80 degrees, or even at least about 85 degrees. Still, the predetermined rotational orientation as defined by therotational angle201 may be not greater than about 90 degrees, such as not greater than about 85 degrees, not greater than about 80 degrees, not greater than about 75 degrees, not greater than about 70 degrees, not greater than about 65 degrees, not greater than about 60 degrees, such as not greater than about 55 degrees, not greater than about 50 degrees, not greater than about 45 degrees, not greater than about 40 degrees, not greater than about 35 degrees, not greater than about 30 degrees, not greater than about 25 degrees, not greater than about 20 degrees, such as not greater than about 15 degrees, not greater than about 10 degrees, or even not greater than about 5 degrees. It will be appreciated that the predetermined rotational orientation can be within a range between any of the above minimum and maximum values.

FIG.6B includes a perspective view illustration of two orientations for the shaped abrasive particles of the embodiments herein. In one embodiment, the shapedabrasive particle683 is in a front orientation relative to thegrinding direction685, which may also relate in a similar manner to one or more dimensions of thesubstrate688 to which the shapedabrasive particle683 is attached. In the front orientation, grinding will be initiated by surface of686 or689, and more particularly, likely initiated atedges671 or672. In a front orientation, the dimension of thickness (t) of the body may be substantially orthogonal (90 degrees plus or minus 45 degrees or even plus or minus 20 degrees) to thegrinding direction685 or corresponding dimensions of the substrate.

In another embodiment, the shapedabrasive particle694 is in a side orientation relative to thegrinding direction685, which may also relate in a similar manner to one or more dimensions of thesubstrate688 to which the shapedabrasive particle694 is attached. In the side orientation, grinding will be initiated by surface of687 or673, and more particularly, likely initiated atedge674. In a side orientation, the dimension of width (W) of the body may be substantially orthogonal (90 degrees plus or minus 45 degrees or even plus or minus 20 degrees) to thegrinding direction685 or corresponding dimensions of thesubstrate688.FIG.7 includes a top-down illustration of a portion of a coated abrasive article according to an embodiment. In one embodiment, the coatedabrasive article700 can include a substrate701 including alongitudinal axis780 and alateral axis781. The coatedabrasive article700 may further include plurality of regions, such as afirst region710, asecond region720, athird region730 and afourth region740. In one aspect, each of theregions710,720,730, and740 can be separated by a channel region750, wherein the channel region750 defines a region the backing that is free of particles. The channel region750 can have any size and shape and may be particularly useful for removing swarf and improved grinding operations. In a particular embodiment, the channel region750 may have a length (i.e., longest dimension) and width (i.e., shortest dimension perpendicular to the length) that is greater than the average spacing between immediately adjacent abrasive particles within any of theregions710,720,730, and740. The channel region750 can be an optional feature for any of the embodiments herein.

According to one embodiment, thefirst region710 can include a group ofabrasive particles711 having a generally random rotational orientation with respect to each other. The group ofabrasive particles711 can be arranged in a random distribution relative to each other, such that there is no discernable short-range order or long-range order with regard to the placement of the group ofabrasive particles711. In one embodiment, the group ofabrasive particles711 may be substantially homogenously distributed within thefirst region710, such that the formation of clumps (two or more particles in contact with each other) is limited.

In another aspect, thesecond region720 can include a group ofabrasive particles721 arranged in a controlled distribution relative to each other. For one embodiment, the group ofabrasive particles721 can have a regular and controlled rotational orientation relative to each other. In another embodiment, the group of shapedabrasive particles721 can have generally the same rotational orientation as defined by the same rotational angle on the backing of the coated abrasive701. In one aspect, the group of shapedabrasive particles721 can be substantially homogenously distributed within thesecond region720, such that the formation of clumps (two or more particles in contact with each other) is limited.

According to another aspect, thethird region730 can include a group ofabrasive particles731 andsecondary particles732. In one embodiment, the group ofabrasive particles731 andsecondary particles732 can be arranged in a controlled distribution relative to each other. For example, the group of shapedabrasive particles731 can have a regular and controlled rotational orientation relative to each other. According to another non-limiting embodiment, the group of shapedabrasive particles731 can have generally one of two types of rotational orientations on the backing of the coated abrasive701. In one instance, the group of shapedabrasive particles731 andsecondary particles732 can be substantially homogenously distributed within thethird region730, such that the formation of clumps (two or more particles in contact with each other) is limited.

For another aspect, afourth region740 can include a group ofabrasive particles741 andsecondary particles742 having a generally random distribution with respect to each other. For example, the group ofabrasive particles741 can have a random rotational orientation with respect to each other. In one embodiment, group ofabrasive particles741 andsecondary particles742 can be arranged in a random distribution relative to each other, such that there is no discernable short-range or long-range order. In another embodiment, the group of shapedabrasive particles741 and thesecondary particles742 can be substantially homogenously distributed within thefourth region740, such that the formation of clumps (two or more particles in contact with each other) is limited.

The coatedabrasive article700 can includedifferent regions710,720,730, and740, each of which can include different groups of particles, such as shaped particles and secondary particles. The coatedabrasive article700 is intended to illustrate the different types of groupings, arrangements, and distributions of particles that may be created using the systems and processes of the embodiments herein. The illustration is not intended to be limited to only those groupings of particles and it will be appreciated that coated abrasive articles can be made including only one region as illustrated inFIG.7. It will also be understood that other coated abrasive articles can be made including a different combination or arrangement of one or more of the regions illustrated inFIG.7.

FIG.8 includes a side-view illustration of abrasive particles on a backing according to an embodiment. In one aspect, the coated abrasive articles of the embodiments herein can have plurality of abrasive particles having a controlled tilt angle, which may facilitate improved performance. To better understand these features,FIG.8 provides a side-view illustration of three abrasive particles in various orientations. It will be appreciated that the coated abrasive articles of the embodiments herein can have various contents of particles in the depicted orientations as described in more detail herein. Thefirst particle802 can have aparticle axis803 extending at aparticular tilt angle804 relative to the surface of thebacking801. Theparticle axis803 can be parallel to the longitudinal axis of thefirst particle802 that defines the length of thefirst particle802. Thefirst particle802 is representative of a particle in an upright orientation having atilt angle804 within a range of greater than 71 degrees to 90 degrees. Thesecond particle811 can have aparticle axis812 extending at aparticular tilt angle813 relative to the surface of thebacking801. Theparticle axis812 can be parallel to a longitudinal axis of thesecond particle811 that defines the length of thesecond particle811. Thesecond particle811 is representative of a particle in a slanted orientation having atilt angle813 within a range of greater than 44 degrees to 71 degrees. Thethird particle821 can have aparticle axis822 extending at a particular tilt angle823 relative to the surface of thebacking801. Theparticle axis822 can be parallel to a longitudinal axis of thethird particle821 that defines the length of thethird particle821. Thethird particle821 is representative of a particle in a flat orientation having a tilt angle823 within a range of at least 0 degrees to not greater than 44 degrees. It will be appreciated that the first, second andthird particles802,811 and821, respectively, can be any type of particle, including but not limited to, shaped abrasive particles as described in the embodiments herein.

According to one aspect, the plurality of abrasive particles on the coated abrasive may have a particular tilt angle, such as at least 2 degrees, such as at least 5 degrees, at least 10 degrees, at least 15 degrees, at least 20 degrees, at least 25 degrees, at least 30 degrees, at least 35 degrees, at least 40 degrees, at least 45 degrees, at least 50 degrees, at least 55 degrees, at least 60 degrees, at least 70 degrees, at least 80 degrees, or even at least 85 degrees. Still, thetilt angle136 may be not greater than about 90 degrees, such as not greater than about 85 degrees, not greater than about 80 degrees, not greater than about 75 degrees, not greater than about 70 degrees, not greater than about 65 degrees, not greater than about 60 degrees, such as not greater than about 55 degrees, not greater than about 50 degrees, not greater than about 45 degrees, not greater than about 40 degrees, not greater than about 35 degrees, not greater than about 30 degrees, not greater than about 25 degrees, not greater than about 20 degrees, such as not greater than about 15 degrees, not greater than about 10 degrees, or even not greater than about 5 degrees. It will be appreciated that the tilt angle can be within a range between any of the above minimum and maximum degrees. The tilt angle may be measured using techniques disclosed in US 2019/0160630 incorporated by reference herein in its entirety.

According to one particular aspect, the content of abrasive particles overlying the backing can be controlled based on the intended application. For example, the plurality abrasive particles can be overlying at least 5% of the total surface area of the backing, such as at least 10% or at least 20% or at least 30% or at least 40% or at least 50% or at least 60% or at least 70% or at least 80% or at least 90%. In still another embodiment, the coated abrasive article may be essentially free of silane.

Furthermore, the abrasive articles of the embodiments herein can have a particular content of particles overlying the substrate. In one embodiment, the particles can define an open coat abrasive product having a coating density of particles (i.e., abrasive particles, secondary particles, or both abrasive particles and secondary particles) of not greater than about 70 particles/cm². In other instances, the density of particles per square centimeter of the abrasive article may be not greater than about 65 particles/cm², such as not greater than about 60 particles/cm², not greater than about 55 particles/cm², or even not greater than about 50 particles/cm². Still, in one non-limiting embodiment, the density of the open coat coated abrasive can be at least about 5 particles/cm², or even at least about 10 particles/cm². It will be appreciated that the density of particles per square centimeter of abrasive article can be within a range between any of the above minimum and maximum values.

In certain instances, the abrasive article can have an open coat density of not greater than about 50% of particles (i.e., abrasive particles or secondary particles or the total of abrasive particles and secondary particles) covering the exterior abrasive surface of the article. In other embodiments, the area of the particles relative to the total area of the surface on which the particles are placed can be not greater than about 40%, such as not greater than about 30%, not greater than about 25%, or even not greater than about 20%. Still, in one non-limiting embodiment, the percentage coating of the particles relative to the total area of the surface can be at least about 5%, such as at least about 10%, at least about 15%, at least about 20%, at least about 25%, at least about 30%, at least about 35%, or even at least about 40%. It will be appreciated that the percent coverage of the particles can be within a range between any of the above minimum and maximum values.

Some abrasive articles may have a particular content of particles (i.e., abrasive particles or secondary particles or the total of abrasive particles and secondary particles) for a given area (e.g., ream, wherein 1 ream=30.66 m²) of the backing. For example, in one embodiment, the abrasive article may utilize a normalized weight of particles of at least about 1 lbs/ream (14.8 grams/m²), such as at least 5 lbs/ream or at least 10 lbs/ream or at least about 15 lbs/ream or at least about 20 lbs/ream or at least about 25 lbs/ream or even at least about 30 lbs/ream. Still, in one non-limiting embodiment, the abrasive article can include a normalized weight of particles of not greater than about 90 lbs/ream (1333.8 grams/m²), such as not greater than 80 lbs/ream or not greater than 70 lbs/ream or not greater than 60 lbs/ream or not greater than about 50 lbs/ream or even not greater than about 45 lbs/ream. It will be appreciated that the abrasive articles of the embodiments herein can utilize a normalized weight of particles within a range between any of the above minimum and maximum values.

In certain instances, the abrasive articles can be used on particular workpieces. A suitable exemplary workpiece can include an inorganic material, an organic material, a natural material, and a combination thereof. According to a particular embodiment, the workpiece can include a metal or metal alloy, such as an iron-based material, a nickel-based material, and the like. In one embodiment, the workpiece can be steel, and more particularly, can consist essentially of stainless steel (e.g., 304 stainless steel).

In still another aspect, the abrasive particles may have a particularly regular shape as defined by solidity. The solidity of the particle is measured by dividing the actual area of the body of a particle as viewed in two dimensions by a convex hull area of the body of the particle as viewed in two-dimensions. Measurement of the actual area and convex hull area of the particles can be conducted by taking images of a statistically relevant sample size of abrasive particles from a batch or a fixed abrasive article. The images can be taken by a suitable optical imaging device (e.g., Olympus DSX) at a suitable magnification (e.g., 10-20×). The images are then saved and analyzed using image processing software, such as ImageJ. A separate image is created for each abrasive particle. Each of the images of the abrasive particles is turned into a black and white only image.FIG.10 includes a two-dimensional black and white image of an abrasive particle according to an embodiment. Using an image like the image ofFIG.10, the image processing software calculates the area in white as the actual area of the body of the particle as viewed in two-dimensions of the length and width or length and thickness. Using the image processing software, a convex hull is drawn around the perimeter of the particle using the shape filter plugin in ImageJ. The imaging processing software then calculates the area inside the convex hull. The solidity is calculated for each particle based on the actual area of each particle divided by the convex hull area. The average solidity is the average of the solidity values for all of the measured particles. The solidity standard deviation is also calculated from all of the solidity values measured from the particles in the sample.

According to one embodiment, the shaped abrasive particles can have a particular solidity that may result from the forming process and may also facilitate improved performance. For example, the shaped abrasive particles can have an average solidity of at least 0.87 or at least 0.88 or at least 0.89 or at least 0.90 or at least 0.91 or at least 0.92 or at least 0.93 or at least 0.94 or at least 0.95 or at least 0.96 or at least 0.97. In another non-limiting embodiment, the shaped abrasive particles may have an average solidity of not greater than 0.9999 or not greater than 0.99 or not greater than 0.98 or not greater than 0.97 or not greater than 0.96 or not greater than 0.95. It will be appreciated that the average solidity of the shaped abrasive particles may be within a range including any of the minimum and maximum values noted above.

In yet another aspect, the shaped abrasive particles may have a particular solidity standard deviation that can be notably distinct from other shaped abrasive particles and indicate a high degree of shape fidelity. For example, the shaped abrasive particles may have a solidity standard deviation of not greater than 0.05 or not greater than 0.045 or not greater than 0.04 or not greater than 0.035 or not greater than 0.030 or not greater than 0.025 or not greater than 0.020. In one non-limiting embodiment, the shaped abrasive particles may have a solidity standard deviation of at least 0.0001 or at least 0.001 or at least 0.01 or at least 0.015 or at least 0.020. It will be appreciated that the solidity standard deviation can be within a range including any of the minimum and maximum values noted above.

According to one embodiment, the plurality of abrasive particles can have a particular solidity that may result of the forming process and may also facilitate improved performance. For example, the plurality of abrasive particles can have an average batch solidity of at least 0.87 or at least 0.88 or at least 0.89 or at least 0.90 or at least 0.91 or at least 0.92 or at least 0.93 or at least 0.94 or at least 0.95 or at least 0.96 or at least 0.97. In another non-limiting embodiment, the plurality of abrasive particles may have an average batch solidity of not greater than 0.9999 or not greater than 0.99 or not greater than 0.98 or not greater than 0.97 or not greater than 0.96 or not greater than 0.95. It will be appreciated that the average batch solidity of the plurality of abrasive particles may be within a range including any of the minimum and maximum values noted above. The average batch solidity of the plurality of abrasive particles may be measured in the same manner as used to measure the average solidity of the shaped abrasive particles, but instead is measured on a sample representative of a batch or a fixed abrasive article.

In yet another aspect, the plurality of abrasive particles may have a particular batch solidity standard deviation that can be notably distinct from other shaped abrasive particles and indicate a high degree of shape fidelity. For example, the plurality of abrasive particles may have a batch solidity standard deviation of not greater than 0.05 or not greater than 0.045 or not greater than 0.04 or not greater than 0.035 or not greater than 0.030 or not greater than 0.025 or not greater than 0.020. In one non-limiting embodiment, the plurality of abrasive particles may have a batch solidity standard deviation of at least 0.0001 or at least 0.001 or at least 0.01 or at least 0.015 or at least 0.020. It will be appreciated that the batch solidity standard deviation can be within a range including any of the minimum and maximum values noted above.

In another embodiment, the shaped abrasive particles may have a particular sharpness that may facilitate improved performance. In at least one embodiment, the body of the shaped abrasive particles can have a sharpness that is not greater than 200 microns or not greater than 180 microns or not greater than 160 microns or not greater than 140 microns or not greater than 120 microns or not greater than 110 microns or not greater than 100 microns or not greater than 90 microns or not greater than 80 microns or not greater than 70 microns. Still, in one non-limiting embodiment, the sharpness can be at least 10 microns or at least 20 microns or at least 30 microns. It will be appreciated that the sharpness can be within a range including any of the minimum and maximum values noted above. Furthermore, it will be appreciated that the sharpness values can be average sharpness calculated from a statistically relevant sample set of abrasive particles.

In another embodiment, a plurality of abrasive particles may have a particular average batch sharpness that may facilitate improved performance. In at least one embodiment, the average batch sharpness may be not greater than 200 microns or not greater than 180 microns or not greater than 160 microns or not greater than 140 microns or not greater than 120 microns or not greater than 110 microns or not greater than 100 microns or not greater than 90 microns or not greater than 80 microns or not greater than 70 microns. Still, in one non-limiting embodiment, the average batch sharpness can be at least 10 microns or at least 20 microns or at least 30 microns. It will be appreciated that the average batch sharpness can be within a range including any of the minimum and maximum values noted above.

Sharpness can be measured using two-dimensional imaging analysis of the abrasive particles. A plurality of shaped abrasive particles are mounted and set on a stage for imaging. Imaging may be completed via an optical microscope such asOlympus DSX 700 at a suitable magnification, such as 10-20×. After taking a suitable image of a suitable statistically relevant sample size of the particles (e.g., at least 200 particles) the images of each of the particles is saved. The sharpness is measured for each particle by image processing software (e.g., ImageJ). Each of the images is converted to a black and white image via Otsu's method where the white pixels represent the body of the particle. A skeletonized image of each particle is then created from each black and white image using the skeletonize function of the software. SeeFIG.11. The distance from theboundary1101 of the body to theterminal points1102,1103,1104, and1105 of the skeleton are evaluated by smallestfit circles1112,1113,1114, and1115 at the terminal points1102-1105, respectively. The smallest fit circles1112-1115 have a center at the terminal points1102-1105 and at least one point on the circumference of each smallest fit circle1112-1115 intersects at least a point on theboundary1101 of the body. The number of smallest fit circles can vary depending upon the terminal points of the skeleton. The radius of each circle is measured in pixels and converted to microns. The sharpness of a single abrasive particle is an individual average of the measured radii of the smallest fit circles1112-1115 in a single particle. An average batch sharpness can be calculated from the individual average values for all particles in the plurality of particles. As will be understood, low radii circles represent sharper corners than high radii circles, thus the lower the sharpness value, the better the relative sharpness.

Many different aspects and embodiments are possible. Some of those aspects and embodiments are described herein. After reading this specification, skilled artisans will appreciate that those aspects and embodiments are only illustrative and do not limit the scope of the present invention. Embodiments may be in accordance with any one or more of the embodiments as listed below.

EMBODIMENTS

Embodiment 1. A plurality of extruded shaped abrasive particles comprising an average solidity of at least 0.87.

Embodiment 2. The plurality of extruded shaped abrasive particles of embodiment 1, wherein the average solidity is at least 0.88 or at least 0.89 or at least 0.90 or at least 0.91 or at least 0.92 or at least 0.93 or at least 0.94 or at least 0.95 or at least 0.96 or at least 0.97.

Embodiment 3. The plurality of extruded shaped abrasive particles of embodiment 1, wherein the average solidity is not greater than 0.9999 or not greater than 0.99 or not greater than 0.98 or not greater than 0.97 or not greater than 0.96 or not greater than 0.95.

Embodiment 4. The plurality of extruded shaped abrasive particles of embodiment 1, wherein each of the extruded shaped abrasive particles comprises a body and striations extending along an exterior surface of the body in a direction of a length of the body.

Embodiment 5. The plurality of extruded shaped abrasive particles of embodiment 4, wherein the striations:

• • a) extend along a majority of an exterior surface area of the body; or
  • b) extend along a majority of the length of the body; or
  • c) extend in the direction of the length of the body on surfaces that define a width and a thickness of the body; or
  • any combination of a)-c).

Embodiment 6. The plurality of extruded shaped abrasive particles of embodiment 4, wherein each of the particles of the plurality of extruded shaped abrasive particles comprises a body having a plurality of side surfaces extending between the end surfaces, and wherein a majority of the side surfaces have striations.

Embodiment 7. The plurality of extruded shaped abrasive particles of embodiment 6, wherein at least one of the end surfaces is substantially free of striations.

Embodiment 8. The plurality of extruded shaped abrasive particles of embodiment 6, wherein the end surfaces are substantially free of striations.

Embodiment 9. The plurality of extruded shaped abrasive particles of embodiment 1, wherein each of the particles of the plurality of extruded shaped abrasive particles comprises a body having a plurality of side surfaces extending between the end surface, and wherein the end surfaces are substantially parallel to each other.

Embodiment 10. The plurality of extruded shaped abrasive particles of embodiment 9, wherein the end surfaces have an average parallelism not greater than 10 degrees.

Embodiment 11. The plurality of extruded shaped abrasive particles of embodiment 9, wherein the end surfaces have a parallelism at least 0.000001 degrees.

Embodiment 12. The plurality of extruded shaped abrasive particles of embodiment 9, wherein the end surfaces are cut surfaces.

Embodiment 13. The plurality of extruded shaped abrasive particles of embodiment 1, wherein each of the particles of the plurality of extruded shaped abrasive particles comprises a body having a plurality of side surfaces extending between end surfaces, and wherein the end surfaces are cut surfaces.

Embodiment 14. The plurality of extruded shaped abrasive particles of embodiment 1, wherein each of the particles of the plurality of extruded shaped abrasive particles comprises a body having a plurality of side surfaces extending between the end surface, and wherein at least one end surface has a different surface roughness as compared to at least one side surfaces.

Embodiment 15. The plurality of extruded shaped abrasive particles of embodiment 14, wherein at least one of the end surfaces has an average surface roughness Ra1 that is different than an average surface roughness of at least one side surface Ra2.

Embodiment 16. The plurality of extruded shaped abrasive particles of embodiment 15, wherein Ra1 is less than Ra2.

Embodiment 17. The plurality of extruded shaped abrasive particles of embodiment 15, wherein Ra1 is at least 10% less than Ra2 or at least 15% or at least 20% or at least 25% less than Ra2.

Embodiment 18. The plurality of extruded shaped abrasive particles of embodiment 1, wherein the body includes a plurality of side surfaces extending between end surfaces, and wherein the side surfaces have a greater surface area as compared to a total surface area of the end surfaces.

Embodiment 19. The plurality of extruded shaped abrasive particles of embodiment 1, wherein the body includes a plurality of side surfaces extending between end surfaces, and wherein at least a first end surface is joined to a first side surface at a first obtuse angle and joined to a second side surface at a first acute angle.

Embodiment 20. The plurality of extruded shaped abrasive particles of embodiment 19, wherein the first side surface and second side surface are opposite each other across a thickness or width of the body.

Embodiment 21. The plurality of extruded shaped abrasive particles of embodiment 19, wherein the first side surface is substantially parallel to the second side surface.

Embodiment 22. The plurality of extruded shaped abrasive particles of embodiment 19, wherein the first side surface is separate from the second side surface by at least one intervening side surface.

Embodiment 23. The plurality of extruded shaped abrasive particles of embodiment 19, wherein the first obtuse angle and first acute angle are supplementary angles.

Embodiment 24. The plurality of extruded shaped abrasive particles of embodiment 19, wherein the first acute angle is at least 5 degrees or at least 8 degrees or at least 10 degrees or at least 15 degrees or at least 20 degrees or at least 25 degrees or at least 30 degrees or at least 35 degrees or at least 40 degrees or at least 45 degrees.

Embodiment 25. The plurality of extruded shaped abrasive particles of embodiment 19, wherein the first acute angle is not greater than 85 degrees or not greater than 80 degrees or not greater than 70 degrees or not greater than 60 degrees or not greater than 50 degrees or not greater than 40 degrees or not greater than 30 degrees.

Embodiment 26. The plurality of extruded shaped abrasive particles of embodiment 19, wherein the first obtuse angle is at least 95 degrees or at least 100 degrees or at least 110 degrees or at least 120 degrees or at least 130 degrees or at least 140 degrees or at least 150 degrees or at least 160 degrees.

Embodiment 27. The plurality of extruded shaped abrasive particles of embodiment 19, wherein the first obtuse angle is not greater than 175 degrees or not greater than 170 degrees or not greater than 160 degrees or not greater than 150 degrees or not greater than 140 degrees or not greater than 130 degrees.

Embodiment 28. The plurality of extruded shaped abrasive particles of embodiment 19, further comprising a second end surface opposite the first end surface across a length of the body, wherein the second end surface is joined to the first side surface at a second acute angle and joined to the second side surface at a second obtuse angle.

Embodiment 29. The plurality of extruded shaped abrasive particles of embodiment 28, wherein the first obtuse angle and second acute angle are supplementary angles.

Embodiment 30. The plurality of extruded shaped abrasive particles of embodiment 28, wherein the first acute angle and second obtuse angle are supplementary angles.

Embodiment 31. The plurality of extruded shaped abrasive particles of embodiment 28, wherein the first acute angle and second acute angle are complementary angles.

Embodiment 32. The plurality of extruded shaped abrasive particles of embodiment 28, wherein the second acute angle is at least 5 degrees or at least 8 degrees or at least 10 degrees or at least 15 degrees or at least 20 degrees or at least 25 degrees or at least 30 degrees or at least 35 degrees or at least 40 degrees or at least 45 degrees.

Embodiment 33. The plurality of extruded shaped abrasive particles of embodiment 28, wherein the second acute angle is not greater than 85 degrees or not greater than 80 degrees or not greater than 70 degrees or not greater than 60 degrees or not greater than 50 degrees or not greater than 40 degrees or not greater than 30 degrees.

Embodiment 34. The plurality of extruded shaped abrasive particles of embodiment 28, wherein the first acute angle is not more than 20% different than the second acute angle or not more than 18% different or not more than 16% or not more than 14% or not more than 12% or not more than 10% or not more than 8% or not more than 6% or not more than 4% or not more than 2%.

Embodiment 35. The plurality of extruded shaped abrasive particles of embodiment 28, wherein the second obtuse angle is at least 95 degrees or at least 100 degrees or at least 110 degrees or at least 120 degrees or at least 130 degrees or at least 140 degrees or at least 150 degrees or at least 160 degrees.

Embodiment 36. The plurality of extruded shaped abrasive particles of embodiment 28, wherein the second obtuse angle is not greater than 175 degrees or not greater than 170 degrees or not greater than 160 degrees or not greater than 150 degrees or not greater than 140 degrees or not greater than 130 degrees.

Embodiment 37. The plurality of extruded shaped abrasive particles of embodiment 28, wherein the first obtuse angle is not more than 20% different than the second obtuse angle or not more than 18% different or not more than 16% or not more than 14% or not more than 12% or not more than 10% or not more than 8% or not more than 6% or not more than 4% or not more than 2%.

Embodiment 38. The plurality of extruded shaped abrasive particles of embodiment 1, wherein each of the particles of the plurality of extruded shaped abrasive particles comprises a body having a length, a width, and a thickness, wherein length>width>thickness.

Embodiment 39. The plurality of extruded shaped abrasive particles of embodiment 38, wherein the plurality of extruded abrasive particles comprises a primary aspect ratio (length/width) of at least 1.1 or at least 1.2 or at least 1.5 or at least 2 or at least 2.5 or at least 3 or at least 3.5 or at least 4 or at least 4.5 or at least 5 or at least 5.5 or at least 6 or at least 8 or at least 10.

Embodiment 40. The plurality of extruded shaped abrasive particles of embodiment 39, wherein the primary aspect ratio (length/width) is not greater than 1000 or not greater than 100 or not greater than 50 or not greater than 20 or not greater than 10 or not greater than 5 or not greater than 3 or not greater than 2.8.

Embodiment 41. The plurality of extruded shaped abrasive particles of embodiment 38, wherein the plurality of extruded abrasive particles comprises a primary aspect ratio standard deviation [STDEV(length/width)] of not greater than 0.55 or not greater than 0.52 or not greater than 0.50 or not greater than 0.48 or not greater than 0.45 or not greater than 0.42 or not greater than 0.40 or not greater than 0.38 or not greater than 0.35 or not greater than 0.32 or not greater than 0.30 or not greater than 0.28 or not greater than 0.25 or not greater than 0.22 or not greater than 0.20 or not greater than 0.18 or not greater than 0.15.

Embodiment 42. The plurality of extruded shaped abrasive particles of embodiment 41, wherein the primary aspect ratio standard deviation [STDEV(length/width)] is at least 0.01 or at least 0.05 or at least 0.1 or at least 0.15 or at least 0.2 or at least 0.25 or at least 0.30 or at least 0.35 or at least 0.4.

Embodiment 43. The plurality of extruded shaped abrasive particles of embodiment 38, wherein the plurality of extruded abrasive particles comprises a secondary aspect ratio (length/thickness) of at least 1.1 or at least 1.2 or at least 1.5 or at least 2 or at least 2.5 or at least 3 or at least 3.5 or at least 4 or at least 4.5 or at least 5 or at least 5.5 or at least 6 or at least 8 or at least 10.

Embodiment 44. The plurality of extruded shaped abrasive particles of embodiment 43, wherein the secondary aspect ratio (length/thickness) is not greater than 1000 or not greater than 100 or not greater than 50 or not greater than 20 or not greater than 10 or not greater than 5 or not greater than 3 or not greater than 2.8.

Embodiment 45. The plurality of extruded shaped abrasive particles of embodiment 38, wherein the plurality of extruded abrasive particles comprises a secondary aspect ratio standard deviation [STDEV(length/thickness)] of not greater than 0.55 or not greater than 0.52 or not greater than 0.50 or not greater than 0.48 or not greater than 0.45 or not greater than 0.42 or not greater than 0.40 or not greater than 0.38 or not greater than 0.35 or not greater than 0.32 or not greater than 0.30 or not greater than 0.28 or not greater than 0.25 or not greater than 0.22 or not greater than 0.20 or not greater than 0.18 or not greater than 0.15 or not greater than 0.12 or not greater than 0.10.

Embodiment 46. The plurality of extruded shaped abrasive particles of embodiment 45, wherein the secondary aspect ratio standard deviation [STDEV(length/thickness)] is at least 0.01 or at least 0.05 or at least 0.07 or at least 0.1 or at least 0.15 or at least 0.2 or at least 0.25 or at least 0.30 or at least 0.35 or at least 0.4.

Embodiment 47. The plurality of extruded shaped abrasive particles of embodiment 38, wherein the plurality of extruded abrasive particles comprises a tertiary aspect ratio (width/thickness) of at least 0.5 or at least 0.6 or at least 0.7 or at least 0.8 or at least 0.9 or at least 1.0 or at least 1.1 or at least 1.2 or at least 1.3 or at least 1.4 or at least 1.5 or at least 2 or at least 2.5 or at least 3 or at least 4.

Embodiment 48. The plurality of extruded shaped abrasive particles of embodiment 47, wherein the tertiary aspect ratio (width/width) is not greater than 10 or not greater than 8 or not greater than 5 or not greater than 3 or not greater than 2 or not greater than 1.5 or not greater than 1.3 or not greater than 1.1.

Embodiment 49. The plurality of extruded shaped abrasive particles of embodiment 38, wherein the plurality of extruded abrasive particles comprises a tertiary aspect ratio standard deviation [STDEV(width/thickness)] of not greater than 0.55 or not greater than 0.52 or not greater than 0.50 or not greater than 0.48 or not greater than 0.45 or not greater than 0.42 or not greater than 0.40 or not greater than 0.38 or not greater than 0.35 or not greater than 0.32 or not greater than 0.30 or not greater than 0.28 or not greater than 0.25 or not greater than 0.22 or not greater than 0.20 or not greater than 0.18 or not greater than 0.15 or not greater than 0.12 or not greater than 0.10.

Embodiment 50. The plurality of extruded shaped abrasive particles of embodiment 49, wherein the tertiary aspect ratio standard deviation [STDEV(width/thickness)] is at least 0.01 or at least 0.05 or at least 0.07 or at least 0.1 or at least 0.15 or at least 0.2 or at least 0.25 or at least 0.30 or at least 0.35 or at least 0.4.

Embodiment 51. The plurality of extruded shaped abrasive particles of embodiment 1, further comprising a solidity standard deviation of not greater than 0.05 or not greater than 0.045 or not greater than 0.04 or not greater than 0.035 or not greater than 0.030 or not greater than 0.025 or not greater than 0.020.

Embodiment 52. The plurality of extruded shaped abrasive particles of embodiment 51, wherein the solidity standard deviation is at least 0.0001 or at least 0.001.

Embodiment 53. A coated abrasive article comprising:

• • a substrate; and
  • a plurality of abrasive particles having an average solidity of at least 0.87 and less than 0.97, wherein each of the abrasive particles of the plurality of abrasive particles comprises a body and striations extending along an exterior surface of the body in a direction of a length of the body.

Embodiment 54. The coated abrasive article of embodiment 53, wherein the striations extend along a majority of an exterior surface area of the body.

Embodiment 55. The coated abrasive article of embodiment 53, wherein the striations extend along a majority of the length of the body.

Embodiment 56. The coated abrasive article of embodiment 53, wherein the striations extend in the direction of the length of the body on surfaces that define a width and a thickness of the body.

Embodiment 57. The coated abrasive article of embodiment 53, wherein each of the particles of the plurality of particles is extruded.

Embodiment 58. The coated abrasive article of embodiment 53, wherein the plurality of abrasive particles includes at least 10 grams of abrasive particles or at least 100 grams of abrasive particles or at least 500 grams of abrasive particles or at least 1 kg of abrasive particles or at least 10 kg of abrasive particles.

Embodiment 59. The coated abrasive article of embodiment 53, wherein the plurality of abrasive particles includes at least 10 abrasive particles or at least 20 abrasive particles or at least 30 abrasive particles or at least 50 abrasive particles or at least 100 abrasive particles or at least 500 abrasive particles.

Embodiment 60. The coated abrasive article of embodiment 53, wherein each of the abrasive particles comprises a body having a length, a width, and a thickness, wherein length>width>thickness.

Embodiment 61. The coated abrasive article of embodiment 53, wherein the abrasive particles have a primary aspect ratio (length/width) of at least 1.1 or at least 1.2 or at least 1.5 or at least 2 or at least 2.5 or at least 3 or at least 3.5 or at least 4 or at least 4.5 or at least 5 or at least 5.5 or at least 6 or at least 8 or at least 10.

Embodiment 62. The coated abrasive article of embodiment 53, wherein the primary aspect ratio (length/width) is not greater than 1000 or not greater than 100 or not greater than 50 or not greater than 20 or not greater than 10 or not greater than 5 or not greater than 3 or not greater than 2.8.

Embodiment 63. The coated abrasive article of embodiment 53, wherein the abrasive particles comprise a primary aspect ratio standard deviation [STDEV(length/width)] of not greater than 0.55 or not greater than 0.52 or not greater than 0.50 or not greater than 0.48 or not greater than 0.45 or not greater than 0.42 or not greater than 0.40 or not greater than 0.38 or not greater than 0.35 or not greater than 0.32 or not greater than 0.30 or not greater than 0.28 or not greater than 0.25 or not greater than 0.22 or not greater than 0.20 or not greater than 0.18 or not greater than 0.15.

Embodiment 64. The coated abrasive article of embodiment 53, wherein the primary aspect ratio standard deviation [STDEV(length/width)] is at least 0.01 or at least 0.05 or at least 0.1 or at least 0.15 or at least 0.2 or at least 0.25 or at least 0.30 or at least 0.35 or at least 0.4.

Embodiment 65. The coated abrasive article of embodiment 53, wherein the abrasive particles have a secondary aspect ratio (length/thickness) of at least 1.1 or at least 1.2 or at least 1.5 or at least 2 or at least 2.5 or at least 3 or at least 3.5 or at least 4 or at least 4.5 or at least 5 or at least 5.5 or at least 6 or at least 8 or at least 10.

Embodiment 66. The coated abrasive article of embodiment 53, wherein the secondary aspect ratio (length/thickness) is not greater than 1000 or not greater than 100 or not greater than 50 or not greater than 20 or not greater than 10 or not greater than 5 or not greater than 3 or not greater than 2.8.

Embodiment 67. The coated abrasive article of embodiment 53, wherein the abrasive particles comprise a secondary aspect ratio standard deviation [STDEV(length/thickness)] of not greater than 0.55 or not greater than 0.52 or not greater than 0.50 or not greater than 0.48 or not greater than 0.45 or not greater than 0.42 or not greater than 0.40 or not greater than 0.38 or not greater than 0.35 or not greater than 0.32 or not greater than 0.30 or not greater than 0.28 or not greater than 0.25 or not greater than 0.22 or not greater than 0.20 or not greater than 0.18 or not greater than 0.15 or not greater than 0.12 or not greater than 0.10.

Embodiment 68. The coated abrasive article of embodiment 53, wherein the secondary aspect ratio standard deviation [STDEV(length/thickness)] is at least 0.01 or at least 0.05 or at least 0.07 or at least 0.1 or at least 0.15 or at least 0.2 or at least 0.25 or at least 0.30 or at least 0.35 or at least 0.4.

Embodiment 69. The coated abrasive article of embodiment 53, wherein the abrasive particles have a tertiary aspect ratio (width/thickness) of at least 0.5 or at least 0.6 or at least 0.7 or at least 0.8 or at least 0.9 or at least 1.0 or at least 1.1 or at least 1.2 or at least 1.3 or at least 1.4 or at least 1.5 or at least 2 or at least 2.5 or at least 3 or at least 4.

Embodiment 70. The coated abrasive article of embodiment 53, wherein the tertiary aspect ratio (width/width) is not greater than 10 or not greater than 8 or not greater than 5 or not greater than 3 or not greater than 2 or not greater than 1.5 or not greater than 1.3 or not greater than 1.1.

Embodiment 71. The coated abrasive article of embodiment 53, wherein the abrasive particles comprise a tertiary aspect ratio standard deviation [STDEV(width/thickness)] of not greater than 0.55 or not greater than 0.52 or not greater than 0.50 or not greater than 0.48 or not greater than 0.45 or not greater than 0.42 or not greater than 0.40 or not greater than 0.38 or not greater than 0.35 or not greater than 0.32 or not greater than 0.30 or not greater than 0.28 or not greater than 0.25 or not greater than 0.22 or not greater than 0.20 or not greater than 0.18 or not greater than 0.15 or not greater than 0.12 or not greater than 0.10.

Embodiment 72. The coated abrasive article of embodiment 53, wherein the tertiary aspect ratio standard deviation [STDEV(width/thickness)] is at least 0.01 or at least 0.05 or at least 0.07 or at least 0.1 or at least 0.15 or at least 0.2 or at least 0.25 or at least 0.30 or at least 0.35 or at least 0.4.

Embodiment 73. The coated abrasive article of embodiment 53, wherein each of the abrasive particles of the plurality of abrasive particles comprises a body having a length, a width, and a thickness, wherein length>width>thickness.

Embodiment 74. The coated abrasive article of embodiment 73, wherein the plurality of abrasive particles comprises a primary aspect ratio [B(length/width)] of at least 1.1 or at least 1.2 or at least 1.5 or at least 2 or at least 2.5 or at least 3 or at least 3.5 or at least 4 or at least 4.5 or at least 5 or at least 5.5 or at least 6 or at least 8 or at least 10.

Embodiment 75. The coated abrasive article of embodiment 74, wherein the primary aspect ratio [B(length/width)] is not greater than 1000 or not greater than 100 or not greater than 50 or not greater than 20 or not greater than 10 or not greater than 5 or not greater than 3 or not greater than 2.8.

Embodiment 76. The coated abrasive article of embodiment 73, wherein the plurality of abrasive particles comprises a primary aspect ratio standard deviation [STDEV-B(length/width)] of not greater than 0.55 or not greater than 0.52 or not greater than 0.50 or not greater than 0.48 or not greater than 0.45 or not greater than 0.42 or not greater than 0.40 or not greater than 0.38 or not greater than 0.35 or not greater than 0.32 or not greater than 0.30 or not greater than 0.28 or not greater than 0.25 or not greater than 0.22 or not greater than 0.20 or not greater than 0.18 or not greater than 0.15.

Embodiment 77. The coated abrasive article of embodiment 76, wherein the primary aspect ratio standard deviation [STDEV-B(length/width)] is at least 0.01 or at least 0.05 or at least 0.1 or at least 0.15 or at least 0.2 or at least 0.25 or at least 0.30 or at least 0.35 or at least 0.4.

Embodiment 78. The coated abrasive article of embodiment 73, wherein the plurality of abrasive particles comprises a secondary aspect ratio [B(length/thickness)] of at least 1.1 or at least 1.2 or at least 1.5 or at least 2 or at least 2.5 or at least 3 or at least 3.5 or at least 4 or at least 4.5 or at least 5 or at least 5.5 or at least 6 or at least 8 or at least 10.

Embodiment 79. The coated abrasive article of embodiment 78, wherein the secondary aspect ratio [B(length/thickness)] is not greater than 1000 or not greater than 100 or not greater than 50 or not greater than 20 or not greater than 10 or not greater than 5 or not greater than 3 or not greater than 2.8 or not greater than 1.3 or not greater than 1.1.

Embodiment 80. The coated abrasive article of embodiment 73, wherein the plurality of particles comprises a secondary aspect ratio standard deviation [STDEV-B(length/thickness)] of not greater than 0.55 or not greater than 0.52 or not greater than 0.50 or not greater than 0.48 or not greater than 0.45 or not greater than 0.42 or not greater than 0.40 or not greater than 0.38 or not greater than 0.35 or not greater than 0.32 or not greater than 0.30 or not greater than 0.28 or not greater than 0.25 or not greater than 0.22 or not greater than 0.20 or not greater than 0.18 or not greater than 0.15 or not greater than 0.12 or not greater than 0.10.

Embodiment 81. The coated abrasive article ofembodiment 80, wherein the secondary aspect ratio standard deviation [STDEV-B(length/thickness)] is at least 0.01 or at least 0.05 or at least 0.07 or at least 0.1 or at least 0.15 or at least 0.2 or at least 0.25 or at least 0.30 or at least 0.35 or at least 0.4.

Embodiment 82. The coated abrasive article of embodiment 73, wherein the plurality of abrasive particles comprises a tertiary aspect ratio [B(width/thickness)] of at least 0.5 or at least 0.6 or at least 0.7 or at least 0.8 or at least 0.9 or at least 1.0 or at least 1.1 or at least 1.2 or at least 1.3 or at least 1.4 or at least 1.5 or at least 2 or at least 2.5 or at least 3 or at least 4.

Embodiment 83. The coated abrasive article of embodiment 82, wherein the tertiary aspect ratio [B(width/width)] is not greater than 10 or not greater than 8 or not greater than 5 or not greater than 3 or not greater than 2 or not greater than 1.5 or not greater than 1.3 or not greater than 1.1.

Embodiment 84. The coated abrasive article of embodiment 73, wherein the plurality of abrasive particles comprises a tertiary aspect ratio standard deviation [STDEV-B(width/thickness)] of not greater than 0.55 or not greater than 0.52 or not greater than 0.50 or not greater than 0.48 or not greater than 0.45 or not greater than 0.42 or not greater than 0.40 or not greater than 0.38 or not greater than 0.35 or not greater than 0.32 or not greater than 0.30 or not greater than 0.28 or not greater than 0.25 or not greater than 0.22 or not greater than 0.20 or not greater than 0.18 or not greater than 0.15 or not greater than 0.12 or not greater than 0.10.

Embodiment 85. The coated abrasive article of embodiment 84, wherein the tertiary aspect ratio standard deviation [STDEV-B(width/thickness)] is at least 0.01 or at least 0.05 or at least 0.07 or at least 0.1 or at least 0.15 or at least 0.2 or at least 0.25 or at least 0.30 or at least 0.35 or at least 0.4.

Embodiment 86. The coated abrasive article of embodiment 53, wherein each of the abrasive particles comprises a body including a tip region including a tip of the body, a base region including a base of the body, wherein the base region is at an opposite end of the body from the tip region along a length of the body.

Embodiment 87. The coated abrasive article of embodiment 86, wherein the tip is defined by a convergence of at least 2 surfaces of the body or a convergence of at least 3 surfaces of the body or a convergence of at least 4 surfaces of the body.

Embodiment 88. The coated abrasive article of embodiment 86, wherein the tip includes a tip edge having a length that is less than an average width or average thickness of the body.

Embodiment 89. The coated abrasive article of embodiment 86, wherein the tip comprises a tip edge having a wedge shape defined by a convergence of side surfaces in the dimension of the width of the particle, wherein a tip edge length is substantially similar to a thickness of the body.

Embodiment 90. The coated abrasive article of embodiment 86, wherein the tip comprises a tip edge having a tip edge length that is not greater than 99% of the average thickness of the body or not greater than 95% or not greater than 90% or not greater than 85% or not greater than 80% or not greater than 75% or not greater than 70% or not greater than 60% or not greater than 50% or not greater than 40% or not greater than 30% of the average thickness of the body.

Embodiment 91. The coated abrasive article of embodiment 90, wherein the tip edge length is at least 20% of the average thickness of the body or at least 30% or at least 40% or at least 50% or at least 60% or at least 70% or at least 80% or at least 90% or at least 95%.

Embodiment 92. The coated abrasive article of embodiment 86, wherein the tip includes a tip edge having a length that is less than an average width of the body.

Embodiment 93. The coated abrasive article of embodiment 92, wherein the tip edge length is not greater than 99% of the average width or not greater than 95% or not greater than 90% or not greater than 85% or not greater than 80% or not greater than 75% or not greater than 70% or not greater than 60% or not greater than 50% or not greater than 40% or not greater than 30% of the average width.

Embodiment 94. The coated abrasive article of embodiment 93, wherein the tip edge length is at least 0.1% of the average width or at least 1% or at least 2% or at least 3% or at least 5% or at least 8% or at least 10% or at least 12% or at least 15% or at least 20%.

Embodiment 95. The coated abrasive article of embodiment 86, wherein the tip includes a tip edge having a length substantially similar to the thickness of the body.

Embodiment 96. The coated abrasive article of embodiment 86, wherein the tip region is defined by a taper including a reduction in the width or thickness of the body over a tip region length.

Embodiment 97. The coated abrasive article of embodiment 86, wherein the tip region is defined by a taper including a reduction in the width of the body over a tip region length.

Embodiment 98. The coated abrasive article of embodiment 97, wherein the tip region is defined by a taper including a reduction in the width and thickness of the body over a tip region length.

Embodiment 99. The coated abrasive article of embodiment 97, wherein the tip region is defined by a taper including a change in the width of the body that is greater than a change in the thickness of the body in the tip region.

Embodiment 100. The coated abrasive article of embodiment 97, wherein the tip region is defined by a taper including a change in the width of the body and wherein the thickness is substantially the same throughout the length of the tip region.

Embodiment 101. The coated abrasive article of embodiment 86, wherein the tip region comprises an asymmetric taper including a first surface and a second surface, wherein the first surface has a different contour as compared to the second surface.

Embodiment 102. The coated abrasive article of embodiment 86, wherein the base comprises a projection extending from the body, wherein the projection extends at an angle relative to a longitudinal axis of the body.

Embodiment 103. The coated abrasive article of embodiment 86, wherein the base region comprises a base including a base surface, wherein the base surface is angled relative to the longitudinal axis of the body.

Embodiment 104. The coated abrasive article of embodiment 86, wherein the base region comprises a base including a base surface, wherein the base surface is angled relative to the longitudinal axis of the body.

Embodiment 105. The coated abrasive article of embodiment 104, wherein the base surface is angled at an acute angle relative to the longitudinal axis of the body.

Embodiment 106. The coated abrasive article ofembodiment 105, wherein the base surface is angled at not greater than 90 degrees relative to the longitudinal axis of the body or not greater than 88 degrees or not greater than 86 degrees or not greater than 84 degrees or not greater than 82 degrees or not greater than 80 degrees or not greater than 75 degrees or not greater than 70 degrees or not greater than 65 degrees or not greater than 60 degrees or not greater than 55 degrees or not greater than 50 degrees or not greater than 45 degrees or not greater than 40 degrees.

Embodiment 107. The coated abrasive article ofembodiment 106, wherein the base surface is angled at an angle of at least 5 degrees relative to the longitudinal axis of the body or at least 10 degrees or at least 15 degrees or at least 20 degrees or at least 25 degrees or at least 30 degrees or at least 35 degrees or at least 40 degrees or at least 45 degrees or at least 50 degrees or at least 55 degrees.

Embodiment 108. The coated abrasive article of embodiment 86, wherein the base comprises a base surface including peaks and valleys.

Embodiment 109. The coated abrasive article ofembodiment 108, wherein the arrangement of peaks and valleys is a random arrangement of peaks and valleys.

Embodiment 110. The coated abrasive article of embodiment 86, wherein the base comprises a base surface having a surface roughness greater than a surface roughness of a side surface of the body in an elongated region or the tip region.

Embodiment 111. The coated abrasive article of embodiment 86, wherein the base comprises a base surface having a plurality of peaks, wherein at least one peak of the plurality of peaks has a tip radius less than a tip radius of the tip of the body.

Embodiment 112. The coated abrasive article ofembodiment 111, wherein at least 2 different peaks of the plurality of peaks each have a tip radius less than a tip radius of the tip of the body.

Embodiment 113. The coated abrasive article of embodiment 86, wherein the base comprises a primary peak as viewed in two dimensions define by the length and the width, wherein the primary peak comprises a primary peak angle of at least 45 degrees and not greater than 150 degrees.

Embodiment 114. The coated abrasive article ofembodiment 113, wherein the primary peak angle is at least 50 degrees or at least 55 or at least 60 degrees or at least 65 degrees or at least 70 degrees or at least 75 degrees or at least 80 degrees or at least 85 degrees or at least 90 degrees or at least 95 degrees or at least 100 degrees.

Embodiment 115. The coated abrasive article ofembodiment 113, wherein the primary peak angle is not greater than 145 degrees or not greater than 140 degrees or not greater than 135 degrees or not greater than 130 degrees or not greater than 125 degrees or not greater than 120 degrees or not greater than 115 degrees or not greater than 110 degrees or not greater than 100 degrees or not greater than 95 degrees.

Embodiment 116. The coated abrasive article of embodiment 86, wherein the base comprises a base surface that is defined by one or more facets having a substantially planar surface extending toward a primary peak of the base surface.

Embodiment 117. The coated abrasive article of embodiment 116, wherein the base surface comprises at least two facets that are abutting each other and define a common edge extending between the two facets.

Embodiment 118. The coated abrasive article of embodiment 86, wherein the base comprises a primary peak and a secondary peak separated from each other by a first primary valley as viewed in two-dimensions by a plane defined by the length and thickness of the body or in two-dimensions by a plane defined by the length and width of the body.

Embodiment 119. The coated abrasive article of embodiment 86, wherein the base comprises a primary peak as viewed in two dimensions define by the length and the width, wherein the primary peak comprises a tip sharpness that is greater than a tip sharpness of the tip of the body.

Embodiment 120. The coated abrasive article of embodiment 119, wherein the primary peak tip sharpness, as measured by a tip angle in two-dimensions defined by a plane of the length and width of the body, is at least 5% less than the tip sharpness of the tip of the body, wherein the tip sharpness is measured by a tip angle in two-dimensions defined by the plane of the length and width of the body or at least 8% or at least 10% or at least 12% or at least 15% or at least 20% or at least 25% or at least 30% or at least 40% or at least 50% or at least 60% or at least 70% or at least 80% or at least 90%.

Embodiment 121. The coated abrasive article of embodiment 86, further comprising an elongated region extending between the tip region and the base region.

Embodiment 122. The coated abrasive article of embodiment 121, wherein the elongated region defines a region between the tip region and the base region having a substantially constant width.

Embodiment 123. The coated abrasive article of embodiment 121, wherein the elongated region defines a region between the tip region and the base region having a substantially constant thickness.

Embodiment 124. The coated abrasive article of embodiment 121, wherein the elongated region defines a region having a change in width or thickness of not greater than 10% over the length of the elongated region or not greater than 8% or not greater than 5% or not greater than 3%.

Embodiment 125. The coated abrasive article of embodiment 86, wherein the body is linear for at least a majority of a total length of the body.

Embodiment 126. The coated abrasive article of embodiment 53, further comprising not greater than 50% of agglomerated particles for a total count of particles in the plurality of abrasive particles or not greater than 48% or not greater than 46% or not greater than 44% or not greater than 42% or not greater than 40% or not greater than 38% or not greater than 36% or not greater than 34% or not greater than 32% or not greater than 30% or not greater than 28% or not greater than 26% or not greater than 24% or not greater than 22% or not greater than 20% or not greater than 18% or not greater than 16% or not greater than 14% or not greater than 12% or not greater than 10% or not greater than 8% or not greater than 6% or not greater than 4% or not greater than 2%, wherein the plurality of abrasive particles is free of agglomerated particles.

Embodiment 127. The coated abrasive article of embodiment 86, wherein the plurality of abrasive particles comprise a taper fraction standard deviation of at least 0.025 or at least 0.028 or at least 0.030 or at least 0.032 or at least 0.035 or at least 0.038 or at least 0.040 or at least 0.042 or at least 0.045 or at least 0.048 or at least 0.050 or at least 0.052 or at least 0.055 or at least 0.058 or at least 0.060.

Embodiment 128. The coated abrasive article of embodiment 127, wherein the taper fraction standard deviation is not greater than 0.090 or not greater than 0.088 or not greater than 0.085 or not greater than 0.082 or not greater than 0.080 or not greater than 0.078 or not greater than 0.075 or not greater than 0.072 or not greater than 0.070 or not greater than 0.068 or not greater than 0.065 or not greater than 0.062 or not greater than 0.060 or not greater than 0.058 or not greater than 0.055 or not greater than 0.052 or not greater than 0.050 or not greater than 0.048 or not greater than 0.045 or not greater than 0.042 or not greater than 0.040.

Embodiment 129. The coated abrasive article of embodiment 127, wherein the taper fraction standard deviation is within a range of at least 0.025 and not greater than 0.090 or within a range of at least 0.025 and not greater than 0.085 or within a range of at least 0.028 and not greater than 0.070 or within a range of at least 0.03 and not greater than 0.06.

Embodiment 130. The coated abrasive article of embodiment 86, wherein the plurality of abrasive particles have an average taper fraction value of at least 0.05 or at least 0.08 or at least 0.1 or at least 0.12 or at least 0.14 or at least 0.16 or at least 0.18 or at least 0.20 or at least 0.22 or at least 0.24 or at least 0.26 or at least 0.28 or at least 0.30 or at least 0.32 or at least 0.34 or at least 0.35.

Embodiment 131. The coated abrasive article of embodiment 130, wherein the average taper fraction value is not greater than 0.8 or not greater than 0.75 or not greater than 0.70 or not greater than 0.65 or not greater than 0.60 or not greater than 0.55 or not greater than 0.50 or not greater than 0.45 or not greater than 0.40 or not greater than 0.35 or not greater than 0.32 or not greater than 0.30 or not greater than 0.28.

Embodiment 132. The coated abrasive article of embodiment 86, further comprising a batch taper fraction standard deviation of at least 0.025 and not greater than 0.090.

Embodiment 133. The coated abrasive article ofembodiment 132, wherein the batch taper fraction standard deviation is at least 0.028 or at least 0.030 or at least 0.032 or at least 0.035 or at least 0.038 or at least 0.040 or at least 0.042 or at least 0.045 or at least 0.048 or at least 0.050 or at least 0.052 or at least 0.055 or at least 0.058 or at least 0.060.

Embodiment 134. The coated abrasive article ofembodiment 133, wherein the batch taper fraction standard deviation is not greater than 0.088 or not greater than 0.085 or not greater than 0.082 or not greater than 0.080 or not greater than 0.078 or not greater than 0.075 or not greater than 0.072 or not greater than 0.070 or not greater than 0.068 or not greater than 0.065 or not greater than 0.062 or not greater than 0.060 or not greater than 0.058 or not greater than 0.055 or not greater than 0.052 or not greater than 0.050 or not greater than 0.048 or not greater than 0.045 or not greater than 0.042 or not greater than 0.040.

Embodiment 135. The coated abrasive article ofembodiment 132, wherein the batch taper fraction standard deviation is within a range of at least 0.025 and not greater than 0.085 or within a range of at least 0.028 and not greater than 0.070 or within a range of at least 0.03 and not greater than 0.060.

Embodiment 136. The coated abrasive of embodiment 53, further comprising an average batch taper fraction value of at least 0.05 or at least 0.08 or at least 0.1 or at least 0.12 or at least 0.14 or at least 0.16 or at least 0.18 or at least 0.20 or at least 0.22 or at least 0.24 or at least 0.26 or at least 0.28 or at least 0.30 or at least 0.32 or at least 0.34 or at least 0.35.

Embodiment 137. The coated abrasive article ofembodiment 136, further comprising an average batch taper fraction value of not greater than 0.80 or not greater than 0.75 or not greater than 0.70 or not greater than 0.65 or not greater than 0.60 or not greater than 0.55 or not greater than 0.50 or not greater than 0.45 or not greater than 0.40 or not greater than 0.35 or not greater than 0.32 or not greater than 0.30 or not greater than 0.28.

Embodiment 138. The coated abrasive article of embodiment 86, wherein each of the abrasive particles of the plurality of abrasive particles comprises a body having an elongation region, and wherein the elongation region taper fraction value is at least 0.15 or at least 0.18 or at least 0.20 or at least 0.25 or at least 0.30 or at least 0.35 or at least 0.40 or at least 0.45 or at least 0.50.

Embodiment 139. The coated abrasive article ofembodiment 138, wherein the elongation region taper fraction value is not greater than 1 or not greater than 0.9 or not greater than 0.8 or not greater than 0.7 or not greater than 0.6.

Embodiment 140. The coated abrasive article ofembodiment 138, further comprising an elongation region taper fraction value standard deviation of at least 0.03 or at least 0.05 or at least 0.08 or at least 0.10 or at least 0.12 or at least 0.16 or at least 0.18.

Embodiment 141. The coated abrasive article ofembodiment 140, wherein the elongation region taper fraction value standard deviation is not greater than 0.3 or not greater than 0.2 or not greater than 0.18 or not greater than 0.16 or not greater than 0.15 or not greater than 0.14

Embodiment 142. The coated abrasive article of embodiment 53, wherein the average solidity is at least 0.88 or at least 0.89 or at least 0.90 or at least 0.91 or at least 0.92 or at least 0.93 or at least 0.94 or at least 0.95 or at least 0.96 or at least 0.97.

Embodiment 143. The coated abrasive article of embodiment 142, wherein the average solidity is not greater than 0.9999 or not greater than 0.99 or not greater than 0.98 or not greater than 0.95.

Embodiment 144. The coated abrasive article of embodiment 53, further comprising an average batch solidity of at least 0.87 or at least 0.88 or at least 0.89 or at least 0.90 or at least 0.91 or at least 0.92 or at least 0.93 or at least 0.94 or at least 0.95 or at least 0.96 or at least 0.97.

Embodiment 145. The coated abrasive article of embodiment 144, wherein the average batch solidity is not greater than 0.9999 or not greater than 0.99 or not greater than 0.98 or not greater than 0.95.

Embodiment 146. The coated abrasive article of embodiment 53, wherein the plurality of abrasive particles comprise a solidity standard deviation of not greater than 0.05 or not greater than 0.045 or not greater than 0.04 or not greater than 0.035 or not greater than 0.030 or not greater than 0.025 or not greater than 0.020.

Embodiment 147. The coated abrasive article ofembodiment 146, wherein the solidity standard deviation is at least 0.0001 or at least 0.001.

Embodiment 148. The coated abrasive article of embodiment 53, further comprising a batch solidity standard deviation of not greater than 0.05 or not greater than 0.045 or not greater than 0.04 or not greater than 0.035 or not greater than 0.030 or not greater than 0.025 or not greater than 0.020.

Embodiment 149. The coated abrasive article ofembodiment 148, wherein the batch solidity standard deviation is at least 0.0001 or at least 0.001.

Embodiment 150. A method for making shaped abrasive particles comprising:

• • forming a mixture into a green body;
  • sectioning the green body with minimal distortion to create a plurality of precursor shaped abrasive particles having an average solidity of at least 0.87.

Embodiment 151. The method of embodiment 150, wherein forming a mixture into a green body includes extruding the mixture through a die.

Embodiment 152. The method of embodiment 150, wherein the die comprises at least one opening that is angled relative to a primary extrusion direction.

Embodiment 153. The method of embodiment 150, wherein sectioning is conducted in a non-perpendicular plane relative to the green body longitudinal axis.

Embodiment 154. The method of embodiment 150, wherein sectioning creates at least one end surface that is a cut surface on an end of a precursor shaped abrasive particle.

Embodiment 155. The method of embodiment 150, wherein the end surface is angled with respect to the side surfaces in a non-perpendicular manner.

Embodiment 156. The method of embodiment 150, wherein each of the precursor shaped abrasive particles comprises a body having a plurality of side surfaces extending between the end surface, and wherein the end surfaces are substantially parallel to each other.

Embodiment 157. The method of embodiment 150, wherein each of the precursor shaped abrasive particles comprises a body including a plurality of side surfaces extending between end surfaces, and wherein the side surfaces have a greater surface area as compared to a total surface area of the end surfaces.

Embodiment 158. The method of embodiment 157, wherein the body includes a plurality of side surfaces extending between end surfaces, and wherein at least a first end surface is joined to a first side surface at a first obtuse angle and joined to a second side surface at a first acute angle.

Embodiment 159. The method of embodiment 158, wherein the first obtuse angle and first acute angle are supplementary angles.

Embodiment 160. The method of embodiment 158, wherein the first acute angle is at least 5 degrees or at least 8 degrees or at least 10 degrees or at least 15 degrees or at least 20 degrees or at least 25 degrees or at least 30 degrees or at least 35 degrees or at least 40 degrees or at least 45 degrees.

Embodiment 161. The method of embodiment 158, wherein the first acute angle is not greater than 85 degrees or not greater than 80 degrees or not greater than 70 degrees or not greater than 60 degrees or not greater than 50 degrees or not greater than 40 degrees or not greater than 30 degrees.

Embodiment 162. The method of embodiment 158, wherein the first obtuse angle is at least 95 degrees or at least 100 degrees or at least 110 degrees or at least 120 degrees or at least 130 degrees or at least 140 degrees or at least 150 degrees or at least 160 degrees.

Embodiment 163. The method of embodiment 158, wherein the first obtuse angle is not greater than 175 degrees or not greater than 170 degrees or not greater than 160 degrees or not greater than 150 degrees or not greater than 140 degrees or not greater than 130 degrees.

Embodiment 164. The method of embodiment 158, further comprising a second end surface opposite the first end surface across a length of the body, wherein the second end surface is joined to the first side surface at a second acute angle and joined to the second side surface at a second obtuse angle.

Embodiment 165. The method of embodiment 164, wherein the first obtuse angle and second acute angle are supplementary angles.

Embodiment 166. The method of embodiment 164, wherein the first acute angle and second obtuse angle are supplementary angles.

Embodiment 167. The method of embodiment 164, wherein the second acute angle is at least 5 degrees or at least 8 degrees or at least 10 degrees or at least 15 degrees or at least 20 degrees or at least 25 degrees or at least 30 degrees or at least 35 degrees or at least 40 degrees or at least 45 degrees.

Embodiment 168. The method of embodiment 164, wherein the second acute angle is not greater than 85 degrees or not greater than 80 degrees or not greater than 70 degrees or not greater than 60 degrees or not greater than 50 degrees or not greater than 40 degrees or not greater than 30 degrees.

Embodiment 169. The method of embodiment 164, wherein the first acute angle is not more than 20% different than the second acute angle or not more than 18% different or not more than 16% or not more than 14% or not more than 12% or not more than 10% or not more than 8% or not more than 6% or not more than 4% or not more than 2%.

Embodiment 170. The method of embodiment 164, wherein the second obtuse angle is at least 95 degrees or at least 100 degrees or at least 110 degrees or at least 120 degrees or at least 130 degrees or at least 140 degrees or at least 150 degrees or at least 160 degrees.

Embodiment 171. The method of embodiment 164, wherein the second obtuse angle is not greater than 175 degrees or not greater than 170 degrees or not greater than 160 degrees or not greater than 150 degrees or not greater than 140 degrees or not greater than 130 degrees.

Embodiment 172. The method of embodiment 164, wherein the first obtuse angle is not more than 20% different than the second obtuse angle or not more than 18% different or not more than 16% or not more than 14% or not more than 12% or not more than 10% or not more than 8% or not more than 6% or not more than 4% or not more than 2%.

Embodiment 173. The method of embodiment 150, wherein sectioning includes simultaneous sectioning of the green body during forming of the green body.

Embodiment 174. The method of embodiment 150, wherein sectioning includes continuous and simultaneous sectioning of portions of the green body while forming of the green body.

Embodiment 175. The method of embodiment 150, further comprising treating at least one surface of the green body after forming and before sectioning, wherein treating can include at least one of forming of an additive on at least one surface of the green body, forming a coating on at least a portion of the green body, wrapping at least a portion of the green body, changing the temperature of the green body.

Embodiment 176. The method of embodiment 175, wherein sectioning is conducted after treating.

Embodiment 177. The method of embodiment 150, wherein sectioning includes addition of at least one sectioning additive to the sectioning mechanism to minimize distortion of the green body during sectioning.

Embodiment 178. The method of embodiment 150, wherein the average solidity of the green body is at least 0.88 or at least 0.89 or at least 0.90 or at least 0.91 or at least 0.92 or at least 0.93 or at least 0.94 or at least 0.95 or at least 0.96 or at least 0.97.

Embodiment 179. The method of embodiment 150, wherein the average solidity of the green body is not greater than 0.9999 or not greater than 0.99 or not greater than 0.98 or not greater than 0.97 or not greater than 0.96 or not greater than 0.95.

Embodiment 180. The method of embodiment 150, further comprising sintering the green body to form a plurality of shaped abrasive particles having an average solidity of at least 0.87.

Embodiment 181. The shaped abrasive particles, fixed abrasive article, or method of any of the preceding embodiments, wherein the body of the shaped abrasive particle comprises a cross-sectional shape selected from the group consisting of a regular polygon, an irregular polygon, an ellipse, a circle or any combination thereof.

EXAMPLESExample 1

Shaped abrasive particles were made according to the following conditions. A mixture was created including approximately 60-66 wt % boehmite, which was obtained from Sasol Corporation. One suitable type of commercially available boehmite is Disperal. The boehmite was mixed and seeded with 1% alpha alumina seeds relative to the total alumina content of the mixture. The alpha alumina seeds were made by milling of corundum using conventional techniques, described for example in U.S. Pat. No. 4,623,364. The mixture also included 34-40 wt % water and 2.5-7 wt % additional nitric acid. The ingredients were mixed in a planetary mixer of conventional design and mixed under reduced pressure to remove gaseous elements from the mixture (e.g., bubbles). The coil value was approximately 3000 N.

After gelling, the mixture was extruded into a die having a plurality of openings angled at an extrusion angle of 15 degrees relative to the major surface of the die. The die ofFIG.1B is generally representative of the die used. The extrusion rate and sectioning rate were controlled to facilitate formation of a batch of precursor shaped abrasive particles. The precursor shaped abrasive particles were dried overnight at 90 C. The precursor shaped abrasive particles were sintered between 1300-1350° C. for approximately 10 minutes to form shaped abrasive particles. The shaped abrasive particles had end surfaces disposed between side surfaces, wherein the first and second acute angles of the particles was approximately 15-30 degrees. The shaped abrasive particles ofFIG.2A are representative of the particles formed as Sample S1.

The shaped abrasive particles of Sample S1 had a square cross-sectional shape as viewed in the plane of the width and thickness. The shaped abrasive particles of Sample S1 had an average length of approximately 1.5 mm, an average width of approximately 0.6 mm microns and an average thickness of approximately 0.6 mm with a square cross-sectional shape as viewed in the elongated region in the plane of the width and thickness. The shaped abrasive particles of Sample S1 were formed essentially of a seeded sol-gel alumina material having an average grain size of less than 1 micron. The shaped abrasive particles of Sample S1 had a solidity of 0.90 with a standard deviation of approximately 0.06 as measured on 245 shaped abrasive particles.

Example 2

A second sample (i.e., Sample S2) of shaped abrasive particles were made from the mixture used to form the shaped abrasive particles of Sample S1, except that the solids loading was approximately 48-53 wt %. The mixture was extruded through a die having a plurality of openings, each of the openings having rectangular two-dimensional shape with a width of approximately 1100 microns and a thickness of approximately 550 microns. The mixture was sectioned after being extruded through the die openings. Notably, the die used to extrude the mixture of Sample S2 had openings oriented as shown in the embodiment ofFIG.1C. The precursor shaped abrasive particles were dried overnight and sintered between 1300-1350° C. for approximately 10 minutes to form shaped abrasive particles.

The shaped abrasive particles had end surfaces disposed between side surfaces, wherein the first and second acute angles of the particles were approximately 45 degrees. The shaped abrasive particles ofFIG.2B are representative of the particles formed for Sample S2.

The shaped abrasive particles of Sample S2 had a rectangular cross-sectional shape as viewed in the plane of the width and thickness. The shaped abrasive particles of Sample S2 had an average length of approximately 1.46 mm, an average width of approximately 540 microns and an average thickness of approximately 270 microns. The shaped abrasive particles of Sample S1 were formed essentially of a seeded sol-gel alumina material having an average grain size of less than 1 micron. The shaped abrasive particles of Sample S2 had a solidity of 0.94 with a standard deviation of approximately 0.05 as measured on 100 shaped abrasive particles.

A third group of shaped abrasive particles (Sample S3) was formed according to the process used to form the shaped abrasive particles of Sample S2, except that the bodies had a square cross-sectional shape as viewed in the plane defined by width and thickness of the particles. The width and thickness each had dimensions of approximately 550 microns. The average length and solidity of the particles of Sample S3 were substantially the same as for Sample S2.

A fourth group of shaped abrasive particles (Sample S4) was formed according to the process used to form the shaped abrasive particles of Sample S2, except that the bodies had a triangular cross-sectional shape as viewed in the plane defined by width and thickness of the particles. The cross-sectional shape was an isosceles triangle with a width of approximately 1500 microns and thickness of approximately 1100 microns. The average length and solidity of the particles of Sample S3 were substantially the same as for Sample S2.

Example 3

The shaped abrasive particles of Samples S1 and S2 are tested according to a single grit grinding test (SGGT) in two different orientations: 1) a front orientation; and 2) a side orientation, wherein in a front orientation the tall side of the bevel is the first to contact the workpiece, and in a side orientation, the particle is rotated 90 degrees about the length of the body wherein a portion of the tip of the bevel is in contact with the workpiece initially. In conducting the SGGT, one single abrasive particle is held in a grit holder by a bonding material of epoxy. The abrasive particle is secured in the desired orientation (i.e., tip region up orientation or base region up orientation) and moved across a workpiece of 304 stainless steel or Inconel (as reported for a given test) for a scratch length of 8 inches using a wheel speed of 22 m/s and an initial scratch depth of 30 microns. The abrasive particle produces a groove in the workpiece having a cross-sectional area (AR). For each sample set, each shaped abrasive particle completes 15 passes across the 8 inch length, 10 individual particles are tested for each of the orientation and the results are analyzed. The test measures the forces exerted by the grit on the workpiece. The tangential force (Ft) is in the direction that is parallel to the surface of the workpiece and the direction of the groove. The normal force (Fn) perpendicular to the surface of the workpiece is also measured. The combination of manual touch-off by infeeding a spinning grain slowly at micron intervals and net change in the measured cross-sectional area of the groove from beginning to the end of the scratch length is used to determine the shaped abrasive particle wear. The net change in the cross-sectional area of the groove for each pass can be measured. For the SGGT, the net cross-sectional area of the groove is defined as the difference between the cross-sectional area of the groove below the surface and the cross-sectional area of the material displaced above the surface. Performance (Ft/A or Fn/A) is defined as the ratio of the tangential or normal force to the net cross-sectional area of the groove.

FIG.12A includes a plot of median force per total area removed from the workpiece for Sample S1 as compared to conventionally extruded abrasive particles (Sample C1), commercially available from Saint-Gobain as Targa, generally formed according to U.S. Pat. No. 5,090,968A, and randomly shaped crushed grains (Sample C2) on 304 SS. For these particular results, the grains had a random orientation and no particular side or front orientation.FIG.12B includes a plot of median force per total area removed from the workpiece (718 Inconel) for Sample S2, Sample S3, and randomly shaped crushed grains (Sample C2).

The above-disclosed subject matter is to be considered illustrative, and not restrictive, and the appended claims are intended to cover all such modifications, enhancements, and other embodiments, which fall within the true scope of the present invention. Thus, to the maximum extent allowed by law, the scope of the present invention is to be determined by the broadest permissible interpretation of the following claims and their equivalents, and shall not be restricted or limited by the foregoing detailed description.

The Abstract of the Disclosure is provided to comply with Patent Law and is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. In addition, in the foregoing Detailed Description, various features may be grouped together or described in a single embodiment for the purpose of streamlining the disclosure. This disclosure is not to be interpreted as reflecting an intention that the claimed embodiments require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter may be directed to less than all features of any of the disclosed embodiments. Thus, the following claims are incorporated into the Detailed Description, with each claim standing on its own as defining separately claimed subject matter.

Claims (22)

What is claimed is:

1. A plurality of extruded shaped abrasive particles comprising an average solidity of at least 0.87, wherein each of the extruded shaped abrasive particles comprises a body having a length, a width, and a thickness, wherein length>width>thickness, wherein the average solidity is measured in a plane defined by the length and width and wherein the body comprises striations extending along an exterior surface of the body in a direction of a length of the body.

2. The plurality of extruded shaped abrasive particles ofclaim 1, wherein the average solidity is at least 0.90.

3. The plurality of extruded shaped abrasive particles ofclaim 1, wherein the average solidity is not greater than 0.99.

4. The plurality of extruded shaped abrasive particles ofclaim 1, wherein each of the particles of the plurality of extruded shaped abrasive particles comprises a body having a plurality of side surfaces extending between the end surface, and wherein the end surfaces are substantially parallel to each other.

5. The plurality of extruded shaped abrasive particles ofclaim 4, wherein the end surfaces have an average parallelism not greater than 10 degrees.

6. The plurality of extruded shaped abrasive particles ofclaim 4, wherein the end surfaces are cut surfaces.

7. The plurality of extruded shaped abrasive particles ofclaim 1, wherein the body includes a plurality of side surfaces extending between end surfaces, and wherein at least a first end surface is joined to a first side surface at a first obtuse angle and joined to a second side surface at a first acute angle.

8. The plurality of extruded shaped abrasive particles ofclaim 7, wherein the first obtuse angle and first acute angle are supplementary angles.

9. The plurality of extruded shaped abrasive particles ofclaim 1, wherein the plurality of extruded abrasive particles comprises a primary aspect ratio (length/width) of at least 1.1.

10. The plurality of extruded shaped abrasive particles ofclaim 1, wherein the plurality of extruded abrasive particles comprises a primary aspect ratio standard deviation [STDEV(length/width)] of not greater than 0.55.

11. The plurality of extruded shaped abrasive particles ofclaim 1, wherein the plurality of extruded abrasive particles comprises a secondary aspect ratio (length/thickness) of at least 1.1.

12. The plurality of extruded shaped abrasive particles ofclaim 1, wherein the plurality of extruded abrasive particles comprises a secondary aspect ratio standard deviation [STDEV(length/thickness)] of not greater than 0.55.

13. A coated abrasive article comprising:

a substrate; and

a plurality of abrasive particles having an average solidity of at least 0.87, wherein each of the abrasive particles of the plurality of abrasive particles comprises a body having a length, a width, and a thickness, wherein length>width>thickness, wherein the average solidity is measured in a plane defined by the length and width and wherein the body comprises striations extending along an exterior surface of the body in a direction of a length of the body.

14. The coated abrasive article ofclaim 13, wherein the abrasive particles have a primary aspect ratio (length/width) of at least 1.1.

15. The coated abrasive article ofclaim 13, wherein each of the abrasive particles comprises a body including a tip region including a tip of the body, a base region including a base of the body, wherein the base region is at an opposite end of the body from the tip region along a length of the body.

16. The coated abrasive article ofclaim 15, wherein the tip region is defined by a taper including a reduction in the width or thickness of the body over a tip region length.

17. The coated abrasive article ofclaim 15, wherein the base comprises a projection extending from the body, wherein the projection extends at an angle relative to a longitudinal axis of the body.

18. The abrasive particle ofclaim 1, wherein the abrasive particle comprises a ceramic material.

19. The abrasive particle ofclaim 1, wherein the abrasive particle comprises alumina.

20. The abrasive particle ofclaim 4, wherein at least one of the end surfaces is substantially free of striations.

21. The abrasive particle ofclaim 1, wherein the body comprises a theoretical density of at least about 95%.

22. The abrasive particle ofclaim 13, wherein the body comprises a theoretical density of at least about 95%.

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